[Boombox] (notifyPlaybackCompletion) removed playlistCursor dependency
[BoomboxInfoListener] added onBufferingUpdate
[Boombox] fixed getDuration() when player isn't ready
[AudioFileDataProvider] sensible default id, fixed getDuration()
[Boombox] fixed critical typo in resetPlayers
[Boombox] when releasing player, release associated processor, if it exists
[Boombox] prepare data provider on separate thread
[Boombox] implemented shuffle/unshuffle