[gnome-control-center] (3 commits) Non-fast-forward update to branch wip/exalm/appearance

[Alexander Mikhaylenko <alexm src gnome org>]

The branch 'wip/exalm/appearance' 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:

  f7535bc... background: Rename to Appearance
  f9b3e0b... background: Clean up the slideshow icon
  66f4e5a... background: Polish wallpaper thumbnails

Commits added to the branch:

  9218e2e... background: Rename to Appearance
  0e38350... background: Clean up the slideshow icon
  762d8af... background: Polish wallpaper thumbnails