Bug#608859: rhythmbox: Some keyboard shortcuts don't work when editing a playlist title

[Aaron Barany]

I apologize for the double post, but I just discovered another quirk with
the behavior. If you have a song selected in the song section of the UI and
press ctrl-X for cut, it will remove the song from the playlist instead of
cutting the text. If there's no song selected, it will cut the text as
expected.