Create album objects on the device when transferring songs, and delete

2009-03-30  Jonathan Matthew  <jonathan@d14n.org>

	* plugins/mtpdevice/rb-mtp-source.c: (rb_mtp_source_init),
	(rb_mtp_source_constructor), (rb_mtp_source_finalize),
	(load_mtp_db_idle_cb), (add_track_to_album),
	(remove_track_from_album), (impl_delete), (transfer_track),
	(impl_track_added), (artwork_notify_cb):
	Create album objects on the device when transferring songs, and delete
	them when the last song is removed.  If all of the existing albums
	have zero tracks, try to rebuild the albums when reading the song
	list.  This helps with some odd devices that forget all album contents
	when they restart.

	If the device supports the JPEG file type, request album art when
	transferring songs, and send it to the device as a 'representative
	sample' of the album.

svn path=/trunk/; revision=6264