remove unused code
refactor and fix Music (getAlbumInfo must return unfiltered artist)
remove useless code
make MPD try albumartist first for songs of album
on "go to album", use albumartist if existent
Merge pull request #323 from hurzl/upstr

Make "Go to Album" use AlbumArtist if existent
fix refactoring error
Merge pull request #324 from hurzl/upstr

fix refactoring error