Remove complete album of selected song in playlist

Added item to song's popup menu in playlist.
If song has an Album Artist, it is used, else Artist.
followup to "Remove complete album"
Merge branch 'master' of https://github.com/hurzl/dmix into hurzl-master

Conflicts:
	MPDroid/src/com/namelessdev/mpdroid/fragments/NowPlayingSmallFragment.java