youtube/dailymotion)
The structure of subtitles was refined, you only need to implement one
method that returns a dictionnary of the available subtitles (lang, url) to
support all the subtitle options in a website. I updated the subtitle
downloaders for youtube/dailymotion to show how it works.
generic subtitle download.
The idea is that all subtitle downloaders must descend from SubtitlesIE
and implement only three basic methods to achieve the complete subtitle
download functionality. This will allow to reduce the code in YoutubeIE
once it is rewritten.
