This adds support for libquvi 0.9.x, and these features:
- start time (part of youtube URL)
- youtube subtitles
- alternative source switching ('l' and 'L' keys)
- youtube playlists
Note that libquvi 0.9 is still in development. Although this seems to
be API stable now, it looks like there will be a 1.0 release, which is
supposed to be the next stable release and the actual successor of
libquvi 0.4.x.
