[gnome-music] (23 commits) ...playlists: Update copyright header

[Jean Felder <jfelder src gnome org>]

Summary of changes:

  72a7173... query: Remove unused method clear_playlist (*)
  e060db7... playlists: Remove unecessary method clear_playlist (*)
  fcd33f4... playlistsview: Remove unused attribute _current_playlist_in (*)
  736b5ef... playlists: Remove unused signal song-removed-from-playlist (*)
  a643c1c... playlists: Manage playlists deletion list internally (*)
  619af1d... playlists: Make Playlist a GObject subclass (*)
  4d7fc85... playlists: Add missing __repr__ method to Playlist class (*)
  f2371df... playlists: Turn python-specific fields into GObject propert (*)
  d07f9be... playlists: Dynamically instantiate the smart playlists (*)
  e0a3406... playlists: Add is_smart property to Playlist (*)
  ec7788c... playlists: Add a SmartPlaylist class (*)
  b7835e7... playlists: Manage playlists internally (*)
  c3db50e... playlists: Sort playlists (*)
  45dc9f0... playlistdialog: Use the playlists managed by Playlists (*)
  b2a7762... playlists: Introduce a ready property (*)
  acffc10... playlistsview: Move playlists instantiation in the class (*)
  f41709c... playlistsview: Use the playlists managed by Playlists (*)
  446c8b3... playlists: Remove is_smart_playlist method (*)
  8eb717b... mpris: Use the playlists managed by Playlists (*)
  214bf5a... grilo: Remove unused function populate_playlists (*)
  4b24b7f... playlists: Remove unused signals (*)
  ccd81c9... playlists: reorder imports (*)
  c87507e... playlists: Update copyright header (*)

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