music streaming? major rework coming up... (iOS 8)

known issues:
- song duration not always correct in iOS player
- no shuffling (yet)
- browsing the music library needs better layouts, at least
posters/song info should be improved
- not fully tested (there are way to many different paths to a given
song…)
music support: shuffle! (iOS8)
Channels: "No Items Available"
sprint - rework XML pretty-print decision
Update to latest git