* the iTunesDB format is not 'open' (no specification provided)
  We don't support all features
* GNUpod doesn't like duplicate id's in the GNUtunesDB.xml (<file id="...)
* Smartplaylist support isn't tested very well
* GNUpod doen't like audible.com files (I'll have to look at this later...)
* gnupod_addsong.pl --restore doesn't remove the '\d+_' prefix from
  files without tags
* mktunes.pl -v 0 doesn't overwrite config value
See -> TODO
