[gnome-music] (7 commits) Non-fast-forward update to branch wip/jfelder/core-restore-player-validation

[Jean Felder <jfelder src gnome org>]

The branch 'wip/jfelder/core-restore-player-validation' was changed in a way that was not a fast-forward 
update.
NOTE: This may cause problems for people pulling from the branch. For more information,
please see:

 https://wiki.gnome.org/Git/Help/NonFastForward

Commits removed from the branch:

  210e337... playlistsview: Disable global selection mode event
  c68aee1... baseview: Remove some unused attributes and methods
  a69a1cb... songliststore: Remove unused columns and reorder them
  f47bd1b... songsview: Explain why iter_to_clean is necessary
  78c4a3d... player: Restore song validation
  4fa46ae... player: Try to load the next song if the current one is unp

Commits added to the branch:

  35affa1... playlistsview: Change songs-list valign property to start
  3e58119... playlistsview: Disable global selection mode event
  3bf1da1... baseview: Remove some unused attributes and methods
  0df0fad... songliststore: Remove unused columns and reorder them
  3802044... songsview: Explain why iter_to_clean is necessary
  6292d2d... player: Restore song validation
  475076d... player: Try to load the next song if the current one is unp