[Interfaces] More item roles.

Added TracksList and SingleTrack item types.
Added TrackInfos role.

Refs #1314.
[LMP] Handle TracksList and SingleTracks radio types.

Refs #1314.
[TS] Added AlbumsManager, refs #1314.
[TS] Be a radio, instantiate AlbumsManager, refs #1314.
Merge branch 'master' of github.com:0xd34df00d/leechcraft