Be smarter about getting random albums with art

Just ask the database for what we want instead of asking for more
results, sifting through them, and hoping that we get enough
qualifying results to fulfill the request.

Also drop Random::album(), since it's duplicate code and it makes more
sense for this to live in Album.
javascript change listener prevented the changing of any album/artist drop downs from actually changing
Fix random album
Minor updates to the transcoding documentation
Merge remote-tracking branch 'upstream/master'
initial shot at tagging songs
its ugly and we need some serious jquery UI niceness but we are tagging!!