[gnome-music] (9 commits) ...mpris: Restore goto method

[Jean Felder <jfelder src gnome org>]

Summary of changes:

  4418dbc... playlistsview: Start playing once the model is loaded (*)
  6c25ddf... coremodel: Add an active playlist property (*)
  d67b998... mpris: Use a correct identifier for playlists (*)
  6a9d942... mpris: Restore playlists support (*)
  4b539f7... coremodel: Add playlist type information when a playlist is (*)
  6979998... mpris: Restore update_song_lists support (*)
  5a17935... mpris: Use active_playlist property to activate a playlist (*)
  523e1ce... player: Remove some unused properties and methods (*)
  90749e2... mpris: Restore goto method (*)

(*) This commit already existed in another branch; no separate mail sent