[gnome-music] (9 commits) Non-fast-forward update to branch wip/jfelder/mpris-fix-playlisttype

[Jean Felder <jfelder src gnome org>]

The branch 'wip/jfelder/mpris-fix-playlisttype' 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:

  8b1e328... mpris: Prevent a cash from play call with no playlist

Commits added to the branch:

  4c6972b... window: Make settings variable internal (*)
  c5ed52f... window: Add seperate class to handle placement (*)
  a05e0aa... window: Mark variables private (*)
  fb3faef... window: Centralize overlay addition (*)
  d90af7b... window: Minor style fix (*)
  1cb143d... data: Move ui files to ui/ subdir (*)
  3a6cc1d... data: Rename application.css to org.gnome.Music.css (*)
  2696f98... data: Move initial-state.png to icons/ subdir (*)
  f568801... mpris: Prevent a cash from play call with no playlist

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