TODO file:
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* Make abstract playlists really become size -1 when created as 
  the ones created on the device instead of the current 1 byte size.

* Support abstract MTP album (0xBA03) just like playlists. Too
  bad that Creative Zen Micro do not support them, they group the
  albums by using the metadata instead. Support representative
  sample (i.e. album cover).

* Support playback and volume setting on devices that have it.
  (I don't have one that does - Linus.)

* Make an API that can return several devices not just connect to the
  first one...
