media backand cleanup
Media: only count artists/albums that the current user has songs for
Media: remove empty artists and albums on clear()
Media: only delete songs for the current user when deleting a song by path
Media: only count each album once
Media: some test cases for Collection
Media: fix ampache api
Media: change ampache password hash when the user changes his password
Merge branch 'master' into media
Media: Better xml escaping
Media: set mimetype for ampache xml response
Media: fix xml encoding
Merge pull request #402 from owncloud/media

Cleanup of media backend code