Subtitle names on youtube may have HTML entities

[PinkPandaKatie]

On some videos (e.g. http://www.youtube.com/watch?v=r3QyKmaLvvk), if the name of the subtitle has an apostrophe, this is returned in the XML list as an escaped entity:

<?xml version="1.0" encoding="utf-8" ?><transcript_list docid="-5803958862083277063"><track id="0" name="Derpy&#39;s lyrics" lang_code="en" lang_original="English" lang_translated="English" lang_default="true"/></transcript_list>

This causes it to generate the following URL:

http://www.youtube.com/api/timedtext?lang=en&fmt=srt&name=Derpy%26%2339%3Bs+lyrics&v=r3QyKmaLvvk

Instead of the correct one:

http://www.youtube.com/api/timedtext?lang=en&fmt=srt&name=Derpy%27s+lyrics&v=r3QyKmaLvvk

diff --git a/youtube_dl/extractor/youtube.py b/youtube_dl/extractor/youtube.py
index 8361dda..70b8dec 100644
--- a/youtube_dl/extractor/youtube.py
+++ b/youtube_dl/extractor/youtube.py
@@ -998,7 +998,7 @@ class YoutubeIE(YoutubeBaseInfoExtractor, SubtitlesInfoExtractor):
                 'lang': lang,
                 'v': video_id,
                 'fmt': self._downloader.params.get('subtitlesformat', 'srt'),
-                'name': l[0].encode('utf-8'),
+                'name': unescapeHTML(l[0]).encode('utf-8'),
             })
             url = u'http://www.youtube.com/api/timedtext?' + params
             sub_lang_list[lang] = url

[phihag]

Thanks, fixed.