7 files changed, 1072 insertions, 0 deletions

diff --git a/vendor/github.com/vincent-petithory/dataurl/LICENSE b/vendor/github.com/vincent-petithory/dataurl/LICENSE
new file mode 100644
index 00000000..ae6cb62b
--- /dev/null
+++ b/vendor/github.com/vincent-petithory/dataurl/LICENSE
@@ -0,0 +1,20 @@
+The MIT License (MIT)
+
+Copyright (c) 2014 Vincent Petithory
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of
+this software and associated documentation files (the "Software"), to deal in
+the Software without restriction, including without limitation the rights to
+use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
+the Software, and to permit persons to whom the Software is furnished to do so,
+subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
+IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
diff --git a/vendor/github.com/vincent-petithory/dataurl/README.md b/vendor/github.com/vincent-petithory/dataurl/README.md
new file mode 100644
index 00000000..1ac59ad2
--- /dev/null
+++ b/vendor/github.com/vincent-petithory/dataurl/README.md
@@ -0,0 +1,81 @@
+# Data URL Schemes for Go [![wercker status](https://app.wercker.com/status/6f9a2e144dfcc59e862c52459b452928/s "wercker status")](https://app.wercker.com/project/bykey/6f9a2e144dfcc59e862c52459b452928) [![GoDoc](https://godoc.org/github.com/vincent-petithory/dataurl?status.png)](https://godoc.org/github.com/vincent-petithory/dataurl)
+
+This package parses and generates Data URL Schemes for the Go language, according to [RFC 2397](http://tools.ietf.org/html/rfc2397).
+
+Data URLs are small chunks of data commonly used in browsers to display inline data,
+typically like small images, or when you use the FileReader API of the browser.
+
+Common use-cases:
+
+ * generate a data URL out of a `string`, `[]byte`, `io.Reader` for inclusion in HTML templates,
+ * parse a data URL sent by a browser in a http.Handler, and do something with the data (save to disk, etc.)
+ * ...
+
+Install the package with:
+~~~
+go get github.com/vincent-petithory/dataurl
+~~~
+
+## Usage
+
+~~~ go
+package main
+
+import (
+	"github.com/vincent-petithory/dataurl"
+	"fmt"
+)
+
+func main() {
+	dataURL, err := dataurl.DecodeString(`data:text/plain;charset=utf-8;base64,aGV5YQ==`)
+	if err != nil {
+		fmt.Println(err)
+		return
+	}
+	fmt.Printf("content type: %s, data: %s\n", dataURL.MediaType.ContentType(), string(dataURL.Data))
+	// Output: content type: text/plain, data: heya
+}
+~~~
+
+From a `http.Handler`:
+
+~~~ go
+func handleDataURLUpload(w http.ResponseWriter, r *http.Request) {
+	dataURL, err := dataurl.Decode(r.Body)
+	defer r.Body.Close()
+	if err != nil {
+		http.Error(w, err.Error(), http.StatusBadRequest)
+		return
+	}
+	if dataURL.ContentType() == "image/png" {
+		ioutil.WriteFile("image.png", dataURL.Data, 0644)
+	} else {
+		http.Error(w, "not a png", http.StatusBadRequest)
+	}
+}
+~~~
+
+## Command
+
+For convenience, a `dataurl` command is provided to encode/decode dataurl streams.
+
+~~~
+dataurl - Encode or decode dataurl data and print to standard output
+
+Usage: dataurl [OPTION]... [FILE]
+
+  dataurl encodes or decodes FILE or standard input if FILE is - or omitted, and prints to standard output.
+  Unless -mimetype is used, when FILE is specified, dataurl will attempt to detect its mimetype using Go's mime.TypeByExtension (http://golang.org/pkg/mime/#TypeByExtension). If this fails or data is read from STDIN, the mimetype will default to application/octet-stream.
+
+Options:
+  -a=false: encode data using ascii instead of base64
+  -ascii=false: encode data using ascii instead of base64
+  -d=false: decode data instead of encoding
+  -decode=false: decode data instead of encoding
+  -m="": force the mimetype of the data to encode to this value
+  -mimetype="": force the mimetype of the data to encode to this value
+~~~
+
+## Contributing
+
+Feel free to file an issue/make a pull request if you find any bug, or want to suggest enhancements.
diff --git a/vendor/github.com/vincent-petithory/dataurl/dataurl.go b/vendor/github.com/vincent-petithory/dataurl/dataurl.go
new file mode 100644
index 00000000..7a9fe67e
--- /dev/null
+++ b/vendor/github.com/vincent-petithory/dataurl/dataurl.go
@@ -0,0 +1,291 @@
+package dataurl
+
+import (
+	"bytes"
+	"encoding/base64"
+	"errors"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"net/http"
+	"sort"
+	"strconv"
+	"strings"
+)
+
+const (
+	// EncodingBase64 is base64 encoding for the data url
+	EncodingBase64 = "base64"
+	// EncodingASCII is ascii encoding for the data url
+	EncodingASCII = "ascii"
+)
+
+func defaultMediaType() MediaType {
+	return MediaType{
+		"text",
+		"plain",
+		map[string]string{"charset": "US-ASCII"},
+	}
+}
+
+// MediaType is the combination of a media type, a media subtype
+// and optional parameters.
+type MediaType struct {
+	Type    string
+	Subtype string
+	Params  map[string]string
+}
+
+// ContentType returns the content type of the dataurl's data, in the form type/subtype.
+func (mt *MediaType) ContentType() string {
+	return fmt.Sprintf("%s/%s", mt.Type, mt.Subtype)
+}
+
+// String implements the Stringer interface.
+//
+// Params values are escaped with the Escape function, rather than in a quoted string.
+func (mt *MediaType) String() string {
+	var (
+		buf  bytes.Buffer
+		keys = make([]string, len(mt.Params))
+		i    int
+	)
+	for k := range mt.Params {
+		keys[i] = k
+		i++
+	}
+	sort.Strings(keys)
+	for _, k := range keys {
+		v := mt.Params[k]
+		fmt.Fprintf(&buf, ";%s=%s", k, EscapeString(v))
+	}
+	return mt.ContentType() + (&buf).String()
+}
+
+// DataURL is the combination of a MediaType describing the type of its Data.
+type DataURL struct {
+	MediaType
+	Encoding string
+	Data     []byte
+}
+
+// New returns a new DataURL initialized with data and
+// a MediaType parsed from mediatype and paramPairs.
+// mediatype must be of the form "type/subtype" or it will panic.
+// paramPairs must have an even number of elements or it will panic.
+// For more complex DataURL, initialize a DataURL struct.
+// The DataURL is initialized with base64 encoding.
+func New(data []byte, mediatype string, paramPairs ...string) *DataURL {
+	parts := strings.Split(mediatype, "/")
+	if len(parts) != 2 {
+		panic("dataurl: invalid mediatype")
+	}
+
+	nParams := len(paramPairs)
+	if nParams%2 != 0 {
+		panic("dataurl: requires an even number of param pairs")
+	}
+	params := make(map[string]string)
+	for i := 0; i < nParams; i += 2 {
+		params[paramPairs[i]] = paramPairs[i+1]
+	}
+
+	mt := MediaType{
+		parts[0],
+		parts[1],
+		params,
+	}
+	return &DataURL{
+		MediaType: mt,
+		Encoding:  EncodingBase64,
+		Data:      data,
+	}
+}
+
+// String implements the Stringer interface.
+//
+// Note: it doesn't guarantee the returned string is equal to
+// the initial source string that was used to create this DataURL.
+// The reasons for that are:
+//  * Insertion of default values for MediaType that were maybe not in the initial string,
+//  * Various ways to encode the MediaType parameters (quoted string or url encoded string, the latter is used),
+func (du *DataURL) String() string {
+	var buf bytes.Buffer
+	du.WriteTo(&buf)
+	return (&buf).String()
+}
+
+// WriteTo implements the WriterTo interface.
+// See the note about String().
+func (du *DataURL) WriteTo(w io.Writer) (n int64, err error) {
+	var ni int
+	ni, _ = fmt.Fprint(w, "data:")
+	n += int64(ni)
+
+	ni, _ = fmt.Fprint(w, du.MediaType.String())
+	n += int64(ni)
+
+	if du.Encoding == EncodingBase64 {
+		ni, _ = fmt.Fprint(w, ";base64")
+		n += int64(ni)
+	}
+
+	ni, _ = fmt.Fprint(w, ",")
+	n += int64(ni)
+
+	if du.Encoding == EncodingBase64 {
+		encoder := base64.NewEncoder(base64.StdEncoding, w)
+		ni, err = encoder.Write(du.Data)
+		if err != nil {
+			return
+		}
+		encoder.Close()
+	} else if du.Encoding == EncodingASCII {
+		ni, _ = fmt.Fprint(w, Escape(du.Data))
+		n += int64(ni)
+	} else {
+		err = fmt.Errorf("dataurl: invalid encoding %s", du.Encoding)
+		return
+	}
+
+	return
+}
+
+// UnmarshalText decodes a Data URL string and sets it to *du
+func (du *DataURL) UnmarshalText(text []byte) error {
+	decoded, err := DecodeString(string(text))
+	if err != nil {
+		return err
+	}
+	*du = *decoded
+	return nil
+}
+
+// MarshalText writes du as a Data URL
+func (du *DataURL) MarshalText() ([]byte, error) {
+	buf := bytes.NewBuffer(nil)
+	if _, err := du.WriteTo(buf); err != nil {
+		return nil, err
+	}
+	return buf.Bytes(), nil
+}
+
+type encodedDataReader func(string) ([]byte, error)
+
+var asciiDataReader encodedDataReader = func(s string) ([]byte, error) {
+	us, err := Unescape(s)
+	if err != nil {
+		return nil, err
+	}
+	return []byte(us), nil
+}
+
+var base64DataReader encodedDataReader = func(s string) ([]byte, error) {
+	data, err := base64.StdEncoding.DecodeString(s)
+	if err != nil {
+		return nil, err
+	}
+	return []byte(data), nil
+}
+
+type parser struct {
+	du                  *DataURL
+	l                   *lexer
+	currentAttr         string
+	unquoteParamVal     bool
+	encodedDataReaderFn encodedDataReader
+}
+
+func (p *parser) parse() error {
+	for item := range p.l.items {
+		switch item.t {
+		case itemError:
+			return errors.New(item.String())
+		case itemMediaType:
+			p.du.MediaType.Type = item.val
+			// Should we clear the default
+			// "charset" parameter at this point?
+			delete(p.du.MediaType.Params, "charset")
+		case itemMediaSubType:
+			p.du.MediaType.Subtype = item.val
+		case itemParamAttr:
+			p.currentAttr = item.val
+		case itemLeftStringQuote:
+			p.unquoteParamVal = true
+		case itemParamVal:
+			val := item.val
+			if p.unquoteParamVal {
+				p.unquoteParamVal = false
+				us, err := strconv.Unquote("\"" + val + "\"")
+				if err != nil {
+					return err
+				}
+				val = us
+			} else {
+				us, err := UnescapeToString(val)
+				if err != nil {
+					return err
+				}
+				val = us
+			}
+			p.du.MediaType.Params[p.currentAttr] = val
+		case itemBase64Enc:
+			p.du.Encoding = EncodingBase64
+			p.encodedDataReaderFn = base64DataReader
+		case itemDataComma:
+			if p.encodedDataReaderFn == nil {
+				p.encodedDataReaderFn = asciiDataReader
+			}
+		case itemData:
+			reader, err := p.encodedDataReaderFn(item.val)
+			if err != nil {
+				return err
+			}
+			p.du.Data = reader
+		case itemEOF:
+			if p.du.Data == nil {
+				p.du.Data = []byte("")
+			}
+			return nil
+		}
+	}
+	panic("EOF not found")
+}
+
+// DecodeString decodes a Data URL scheme string.
+func DecodeString(s string) (*DataURL, error) {
+	du := &DataURL{
+		MediaType: defaultMediaType(),
+		Encoding:  EncodingASCII,
+	}
+
+	parser := &parser{
+		du: du,
+		l:  lex(s),
+	}
+	if err := parser.parse(); err != nil {
+		return nil, err
+	}
+	return du, nil
+}
+
+// Decode decodes a Data URL scheme from a io.Reader.
+func Decode(r io.Reader) (*DataURL, error) {
+	data, err := ioutil.ReadAll(r)
+	if err != nil {
+		return nil, err
+	}
+	return DecodeString(string(data))
+}
+
+// EncodeBytes encodes the data bytes into a Data URL string, using base 64 encoding.
+//
+// The media type of data is detected using http.DetectContentType.
+func EncodeBytes(data []byte) string {
+	mt := http.DetectContentType(data)
+	// http.DetectContentType may add spurious spaces between ; and a parameter.
+	// The canonical way is to not have them.
+	cleanedMt := strings.Replace(mt, "; ", ";", -1)
+
+	return New(data, cleanedMt).String()
+}
diff --git a/vendor/github.com/vincent-petithory/dataurl/doc.go b/vendor/github.com/vincent-petithory/dataurl/doc.go
new file mode 100644
index 00000000..56461d04
--- /dev/null
+++ b/vendor/github.com/vincent-petithory/dataurl/doc.go
@@ -0,0 +1,28 @@
+/*
+Package dataurl parses Data URL Schemes
+according to RFC 2397
+(http://tools.ietf.org/html/rfc2397).
+
+Data URLs are small chunks of data commonly used in browsers to display inline data,
+typically like small images, or when you use the FileReader API of the browser.
+
+A dataurl looks like:
+
+	data:text/plain;charset=utf-8,A%20brief%20note
+
+Or, with base64 encoding:
+
+	data:image/vnd.microsoft.icon;name=golang%20favicon;base64,AAABAAEAEBAAAAEAIABoBAAAFgAAACgAAAAQAAAAIAAAAAEAIAAAAAAAAAAAAAAAAAAAAAAAAAAA
+	AAAAAAD///8AVE44//7hdv/+4Xb//uF2//7hdv/+4Xb//uF2//7hdv/+4Xb//uF2//7hdv/+4Xb/
+	/uF2/1ROOP////8A////AFROOP/+4Xb//uF2//7hdv/+4Xb//uF2//7hdv/+4Xb//uF2//7hdv/+
+	...
+	/6CcjP97c07/e3NO/1dOMf9BOiX/TkUn/2VXLf97c07/e3NO/6CcjP/h4uX/////AP///wD///8A
+	////AP///wD///8A////AP///wDq6/H/3N/j/9fZ3f/q6/H/////AP///wD///8A////AP///wD/
+	//8AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
+	AAAAAAAAAAAAAA==
+
+Common functions are Decode and DecodeString to obtain a DataURL,
+and DataURL.String() and DataURL.WriteTo to generate a Data URL string.
+
+*/
+package dataurl
diff --git a/vendor/github.com/vincent-petithory/dataurl/lex.go b/vendor/github.com/vincent-petithory/dataurl/lex.go
new file mode 100644
index 00000000..1a8717f5
--- /dev/null
+++ b/vendor/github.com/vincent-petithory/dataurl/lex.go
@@ -0,0 +1,521 @@
+package dataurl
+
+import (
+	"fmt"
+	"strings"
+	"unicode"
+	"unicode/utf8"
+)
+
+type item struct {
+	t   itemType
+	val string
+}
+
+func (i item) String() string {
+	switch i.t {
+	case itemEOF:
+		return "EOF"
+	case itemError:
+		return i.val
+	}
+	if len(i.val) > 10 {
+		return fmt.Sprintf("%.10q...", i.val)
+	}
+	return fmt.Sprintf("%q", i.val)
+}
+
+type itemType int
+
+const (
+	itemError itemType = iota
+	itemEOF
+
+	itemDataPrefix
+
+	itemMediaType
+	itemMediaSep
+	itemMediaSubType
+	itemParamSemicolon
+	itemParamAttr
+	itemParamEqual
+	itemLeftStringQuote
+	itemRightStringQuote
+	itemParamVal
+
+	itemBase64Enc
+
+	itemDataComma
+	itemData
+)
+
+const eof rune = -1
+
+func isTokenRune(r rune) bool {
+	return r <= unicode.MaxASCII &&
+		!unicode.IsControl(r) &&
+		!unicode.IsSpace(r) &&
+		!isTSpecialRune(r)
+}
+
+func isTSpecialRune(r rune) bool {
+	return r == '(' ||
+		r == ')' ||
+		r == '<' ||
+		r == '>' ||
+		r == '@' ||
+		r == ',' ||
+		r == ';' ||
+		r == ':' ||
+		r == '\\' ||
+		r == '"' ||
+		r == '/' ||
+		r == '[' ||
+		r == ']' ||
+		r == '?' ||
+		r == '='
+}
+
+// See http://tools.ietf.org/html/rfc2045
+// This doesn't include extension-token case
+// as it's handled separatly
+func isDiscreteType(s string) bool {
+	if strings.HasPrefix(s, "text") ||
+		strings.HasPrefix(s, "image") ||
+		strings.HasPrefix(s, "audio") ||
+		strings.HasPrefix(s, "video") ||
+		strings.HasPrefix(s, "application") {
+		return true
+	}
+	return false
+}
+
+// See http://tools.ietf.org/html/rfc2045
+// This doesn't include extension-token case
+// as it's handled separatly
+func isCompositeType(s string) bool {
+	if strings.HasPrefix(s, "message") ||
+		strings.HasPrefix(s, "multipart") {
+		return true
+	}
+	return false
+}
+
+func isURLCharRune(r rune) bool {
+	// We're a bit permissive here,
+	// by not including '%' in delims
+	// This is okay, since url unescaping will validate
+	// that later in the parser.
+	return r <= unicode.MaxASCII &&
+		!(r >= 0x00 && r <= 0x1F) && r != 0x7F && /* control */
+		// delims
+		r != ' ' &&
+		r != '<' &&
+		r != '>' &&
+		r != '#' &&
+		r != '"' &&
+		// unwise
+		r != '{' &&
+		r != '}' &&
+		r != '|' &&
+		r != '\\' &&
+		r != '^' &&
+		r != '[' &&
+		r != ']' &&
+		r != '`'
+}
+
+func isBase64Rune(r rune) bool {
+	return (r >= 'a' && r <= 'z') ||
+		(r >= 'A' && r <= 'Z') ||
+		(r >= '0' && r <= '9') ||
+		r == '+' ||
+		r == '/' ||
+		r == '=' ||
+		r == '\n'
+}
+
+type stateFn func(*lexer) stateFn
+
+// lexer lexes the data URL scheme input string.
+// The implementation is from the text/template/parser package.
+type lexer struct {
+	input          string
+	start          int
+	pos            int
+	width          int
+	seenBase64Item bool
+	items          chan item
+}
+
+func (l *lexer) run() {
+	for state := lexBeforeDataPrefix; state != nil; {
+		state = state(l)
+	}
+	close(l.items)
+}
+
+func (l *lexer) emit(t itemType) {
+	l.items <- item{t, l.input[l.start:l.pos]}
+	l.start = l.pos
+}
+
+func (l *lexer) next() (r rune) {
+	if l.pos >= len(l.input) {
+		l.width = 0
+		return eof
+	}
+	r, l.width = utf8.DecodeRuneInString(l.input[l.pos:])
+	l.pos += l.width
+	return r
+}
+
+func (l *lexer) backup() {
+	l.pos -= l.width
+}
+
+func (l *lexer) ignore() {
+	l.start = l.pos
+}
+
+func (l *lexer) errorf(format string, args ...interface{}) stateFn {
+	l.items <- item{itemError, fmt.Sprintf(format, args...)}
+	return nil
+}
+
+func lex(input string) *lexer {
+	l := &lexer{
+		input: input,
+		items: make(chan item),
+	}
+	go l.run() // Concurrently run state machine.
+	return l
+}
+
+const (
+	dataPrefix     = "data:"
+	mediaSep       = '/'
+	paramSemicolon = ';'
+	paramEqual     = '='
+	dataComma      = ','
+)
+
+// start lexing by detecting data prefix
+func lexBeforeDataPrefix(l *lexer) stateFn {
+	if strings.HasPrefix(l.input[l.pos:], dataPrefix) {
+		return lexDataPrefix
+	}
+	return l.errorf("missing data prefix")
+}
+
+// lex data prefix
+func lexDataPrefix(l *lexer) stateFn {
+	l.pos += len(dataPrefix)
+	l.emit(itemDataPrefix)
+	return lexAfterDataPrefix
+}
+
+// lex what's after data prefix.
+// it can be the media type/subtype separator,
+// the base64 encoding, or the comma preceding the data
+func lexAfterDataPrefix(l *lexer) stateFn {
+	switch r := l.next(); {
+	case r == paramSemicolon:
+		l.backup()
+		return lexParamSemicolon
+	case r == dataComma:
+		l.backup()
+		return lexDataComma
+	case r == eof:
+		return l.errorf("missing comma before data")
+	case r == 'x' || r == 'X':
+		if l.next() == '-' {
+			return lexXTokenMediaType
+		}
+		return lexInDiscreteMediaType
+	case isTokenRune(r):
+		return lexInDiscreteMediaType
+	default:
+		return l.errorf("invalid character after data prefix")
+	}
+}
+
+func lexXTokenMediaType(l *lexer) stateFn {
+	for {
+		switch r := l.next(); {
+		case r == mediaSep:
+			l.backup()
+			return lexMediaType
+		case r == eof:
+			return l.errorf("missing media type slash")
+		case isTokenRune(r):
+		default:
+			return l.errorf("invalid character for media type")
+		}
+	}
+}
+
+func lexInDiscreteMediaType(l *lexer) stateFn {
+	for {
+		switch r := l.next(); {
+		case r == mediaSep:
+			l.backup()
+			// check it's valid discrete type
+			if !isDiscreteType(l.input[l.start:l.pos]) &&
+				!isCompositeType(l.input[l.start:l.pos]) {
+				return l.errorf("invalid media type")
+			}
+			return lexMediaType
+		case r == eof:
+			return l.errorf("missing media type slash")
+		case isTokenRune(r):
+		default:
+			return l.errorf("invalid character for media type")
+		}
+	}
+}
+
+func lexMediaType(l *lexer) stateFn {
+	if l.pos > l.start {
+		l.emit(itemMediaType)
+	}
+	return lexMediaSep
+}
+
+func lexMediaSep(l *lexer) stateFn {
+	l.next()
+	l.emit(itemMediaSep)
+	return lexAfterMediaSep
+}
+
+func lexAfterMediaSep(l *lexer) stateFn {
+	for {
+		switch r := l.next(); {
+		case r == paramSemicolon || r == dataComma:
+			l.backup()
+			return lexMediaSubType
+		case r == eof:
+			return l.errorf("incomplete media type")
+		case isTokenRune(r):
+		default:
+			return l.errorf("invalid character for media subtype")
+		}
+	}
+}
+
+func lexMediaSubType(l *lexer) stateFn {
+	if l.pos > l.start {
+		l.emit(itemMediaSubType)
+	}
+	return lexAfterMediaSubType
+}
+
+func lexAfterMediaSubType(l *lexer) stateFn {
+	switch r := l.next(); {
+	case r == paramSemicolon:
+		l.backup()
+		return lexParamSemicolon
+	case r == dataComma:
+		l.backup()
+		return lexDataComma
+	case r == eof:
+		return l.errorf("missing comma before data")
+	default:
+		return l.errorf("expected semicolon or comma")
+	}
+}
+
+func lexParamSemicolon(l *lexer) stateFn {
+	l.next()
+	l.emit(itemParamSemicolon)
+	return lexAfterParamSemicolon
+}
+
+func lexAfterParamSemicolon(l *lexer) stateFn {
+	switch r := l.next(); {
+	case r == eof:
+		return l.errorf("unterminated parameter sequence")
+	case r == paramEqual || r == dataComma:
+		return l.errorf("unterminated parameter sequence")
+	case isTokenRune(r):
+		l.backup()
+		return lexInParamAttr
+	default:
+		return l.errorf("invalid character for parameter attribute")
+	}
+}
+
+func lexBase64Enc(l *lexer) stateFn {
+	if l.pos > l.start {
+		if v := l.input[l.start:l.pos]; v != "base64" {
+			return l.errorf("expected base64, got %s", v)
+		}
+		l.seenBase64Item = true
+		l.emit(itemBase64Enc)
+	}
+	return lexDataComma
+}
+
+func lexInParamAttr(l *lexer) stateFn {
+	for {
+		switch r := l.next(); {
+		case r == paramEqual:
+			l.backup()
+			return lexParamAttr
+		case r == dataComma:
+			l.backup()
+			return lexBase64Enc
+		case r == eof:
+			return l.errorf("unterminated parameter sequence")
+		case isTokenRune(r):
+		default:
+			return l.errorf("invalid character for parameter attribute")
+		}
+	}
+}
+
+func lexParamAttr(l *lexer) stateFn {
+	if l.pos > l.start {
+		l.emit(itemParamAttr)
+	}
+	return lexParamEqual
+}
+
+func lexParamEqual(l *lexer) stateFn {
+	l.next()
+	l.emit(itemParamEqual)
+	return lexAfterParamEqual
+}
+
+func lexAfterParamEqual(l *lexer) stateFn {
+	switch r := l.next(); {
+	case r == '"':
+		l.emit(itemLeftStringQuote)
+		return lexInQuotedStringParamVal
+	case r == eof:
+		return l.errorf("missing comma before data")
+	case isTokenRune(r):
+		return lexInParamVal
+	default:
+		return l.errorf("invalid character for parameter value")
+	}
+}
+
+func lexInQuotedStringParamVal(l *lexer) stateFn {
+	for {
+		switch r := l.next(); {
+		case r == eof:
+			return l.errorf("unclosed quoted string")
+		case r == '\\':
+			return lexEscapedChar
+		case r == '"':
+			l.backup()
+			return lexQuotedStringParamVal
+		case r <= unicode.MaxASCII:
+		default:
+			return l.errorf("invalid character for parameter value")
+		}
+	}
+}
+
+func lexEscapedChar(l *lexer) stateFn {
+	switch r := l.next(); {
+	case r <= unicode.MaxASCII:
+		return lexInQuotedStringParamVal
+	case r == eof:
+		return l.errorf("unexpected eof")
+	default:
+		return l.errorf("invalid escaped character")
+	}
+}
+
+func lexInParamVal(l *lexer) stateFn {
+	for {
+		switch r := l.next(); {
+		case r == paramSemicolon || r == dataComma:
+			l.backup()
+			return lexParamVal
+		case r == eof:
+			return l.errorf("missing comma before data")
+		case isTokenRune(r):
+		default:
+			return l.errorf("invalid character for parameter value")
+		}
+	}
+}
+
+func lexQuotedStringParamVal(l *lexer) stateFn {
+	if l.pos > l.start {
+		l.emit(itemParamVal)
+	}
+	l.next()
+	l.emit(itemRightStringQuote)
+	return lexAfterParamVal
+}
+
+func lexParamVal(l *lexer) stateFn {
+	if l.pos > l.start {
+		l.emit(itemParamVal)
+	}
+	return lexAfterParamVal
+}
+
+func lexAfterParamVal(l *lexer) stateFn {
+	switch r := l.next(); {
+	case r == paramSemicolon:
+		l.backup()
+		return lexParamSemicolon
+	case r == dataComma:
+		l.backup()
+		return lexDataComma
+	case r == eof:
+		return l.errorf("missing comma before data")
+	default:
+		return l.errorf("expected semicolon or comma")
+	}
+}
+
+func lexDataComma(l *lexer) stateFn {
+	l.next()
+	l.emit(itemDataComma)
+	if l.seenBase64Item {
+		return lexBase64Data
+	}
+	return lexData
+}
+
+func lexData(l *lexer) stateFn {
+Loop:
+	for {
+		switch r := l.next(); {
+		case r == eof:
+			break Loop
+		case isURLCharRune(r):
+		default:
+			return l.errorf("invalid data character")
+		}
+	}
+	if l.pos > l.start {
+		l.emit(itemData)
+	}
+	l.emit(itemEOF)
+	return nil
+}
+
+func lexBase64Data(l *lexer) stateFn {
+Loop:
+	for {
+		switch r := l.next(); {
+		case r == eof:
+			break Loop
+		case isBase64Rune(r):
+		default:
+			return l.errorf("invalid data character")
+		}
+	}
+	if l.pos > l.start {
+		l.emit(itemData)
+	}
+	l.emit(itemEOF)
+	return nil
+}
diff --git a/vendor/github.com/vincent-petithory/dataurl/rfc2396.go b/vendor/github.com/vincent-petithory/dataurl/rfc2396.go
new file mode 100644
index 00000000..e2ea0cac
--- /dev/null
+++ b/vendor/github.com/vincent-petithory/dataurl/rfc2396.go
@@ -0,0 +1,130 @@
+package dataurl
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+	"strings"
+)
+
+// Escape implements URL escaping, as defined in RFC 2397 (http://tools.ietf.org/html/rfc2397).
+// It differs a bit from net/url's QueryEscape and QueryUnescape, e.g how spaces are treated (+ instead of %20):
+//
+// Only ASCII chars are allowed. Reserved chars are escaped to their %xx form.
+// Unreserved chars are [a-z], [A-Z], [0-9], and -_.!~*\().
+func Escape(data []byte) string {
+	var buf = new(bytes.Buffer)
+	for _, b := range data {
+		switch {
+		case isUnreserved(b):
+			buf.WriteByte(b)
+		default:
+			fmt.Fprintf(buf, "%%%02X", b)
+		}
+	}
+	return buf.String()
+}
+
+// EscapeString is like Escape, but taking
+// a string as argument.
+func EscapeString(s string) string {
+	return Escape([]byte(s))
+}
+
+// isUnreserved return true
+// if the byte c is an unreserved char,
+// as defined in RFC 2396.
+func isUnreserved(c byte) bool {
+	return (c >= 'a' && c <= 'z') ||
+		(c >= 'A' && c <= 'Z') ||
+		(c >= '0' && c <= '9') ||
+		c == '-' ||
+		c == '_' ||
+		c == '.' ||
+		c == '!' ||
+		c == '~' ||
+		c == '*' ||
+		c == '\'' ||
+		c == '(' ||
+		c == ')'
+}
+
+func isHex(c byte) bool {
+	switch {
+	case c >= 'a' && c <= 'f':
+		return true
+	case c >= 'A' && c <= 'F':
+		return true
+	case c >= '0' && c <= '9':
+		return true
+	}
+	return false
+}
+
+// borrowed from net/url/url.go
+func unhex(c byte) byte {
+	switch {
+	case '0' <= c && c <= '9':
+		return c - '0'
+	case 'a' <= c && c <= 'f':
+		return c - 'a' + 10
+	case 'A' <= c && c <= 'F':
+		return c - 'A' + 10
+	}
+	return 0
+}
+
+// Unescape unescapes a character sequence
+// escaped with Escape(String?).
+func Unescape(s string) ([]byte, error) {
+	var buf = new(bytes.Buffer)
+	reader := strings.NewReader(s)
+
+	for {
+		r, size, err := reader.ReadRune()
+		if err == io.EOF {
+			break
+		}
+		if err != nil {
+			return nil, err
+		}
+		if size > 1 {
+			return nil, fmt.Errorf("rfc2396: non-ASCII char detected")
+		}
+
+		switch r {
+		case '%':
+			eb1, err := reader.ReadByte()
+			if err == io.EOF {
+				return nil, fmt.Errorf("rfc2396: unexpected end of unescape sequence")
+			}
+			if err != nil {
+				return nil, err
+			}
+			if !isHex(eb1) {
+				return nil, fmt.Errorf("rfc2396: invalid char 0x%x in unescape sequence", r)
+			}
+			eb0, err := reader.ReadByte()
+			if err == io.EOF {
+				return nil, fmt.Errorf("rfc2396: unexpected end of unescape sequence")
+			}
+			if err != nil {
+				return nil, err
+			}
+			if !isHex(eb0) {
+				return nil, fmt.Errorf("rfc2396: invalid char 0x%x in unescape sequence", r)
+			}
+			buf.WriteByte(unhex(eb0) + unhex(eb1)*16)
+		default:
+			buf.WriteByte(byte(r))
+		}
+	}
+	return buf.Bytes(), nil
+}
+
+// UnescapeToString is like Unescape, but returning
+// a string.
+func UnescapeToString(s string) (string, error) {
+	b, err := Unescape(s)
+	return string(b), err
+}
diff --git a/vendor/github.com/vincent-petithory/dataurl/wercker.yml b/vendor/github.com/vincent-petithory/dataurl/wercker.yml
new file mode 100644
index 00000000..3ab8084c
--- /dev/null
+++ b/vendor/github.com/vincent-petithory/dataurl/wercker.yml
@@ -0,0 +1 @@
+box: wercker/default
\ No newline at end of file