-added bpm column to songs
-updated the dbsong class and other to include bpm
-improved DatabaseModel.insertSong so that it can take a DBSong object as
an parameter as well
-forgot to update the insert/update sql queries to include the bpm column
-there was a bug in the DBSong constructor that wasn't properly setting
the bpm value
-DatabaseModel can now range select on BPM and DBTest tests that selection
-created playcount range sql query
-DatabaseModel can now query for song ids based upon a range of play
counts
-DBTests now support testing for play count range
-DBTests are now more flexible, aka got rid of hard bounds for range tests
-updated the db todo file reflect what I have next to work on in the db
-did some formating in the select by playcount sql query
-added more comments in the DBTest and DatabaseModel classes