[gnome-control-center] (15 commits) Non-fast-forward update to branch wip/jsparber/background

[Julian Sparber <jsparber src gnome org>]

The branch 'wip/jsparber/background' 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:

  36e44c8... background: add buttons at bottom the of the gallery
  15fdef2... background: clear settings object in dispose
  ab95ec2... background: resize preview based on window size
  e9b28b6... background: set wallpaper and lockscreen
  ee56969... background: clean up code
  fa25d95... background: refactor cc-background-store
  ed7c68b... background: refactor cc-background-grid-item
  cfc2631... background: cache tumbnail for wallpaper gallery for a redr
  d8ad7dc... background: changed variable names and small style changes
  4b314f5... background: cache slideshow-emblem icon
  74c974c... background: show only top border for gallery view
  a7ff86c... background: adapt meson.build for file changes
  aeec75a... background: change description for open in File and open in
  0f95145... background: use autoptr where possible
  eb60ea0... background: clean up files and code and remove build warnin

Commits added to the branch:

  8e074ae... background: add buttons at bottom of the gallery
  aa6f970... background: clear settings object in dispose
  3027e41... background: resize preview based on window size
  fb23fcc... background: set wallpaper and lockscreen
  34ef941... background: clean up code
  7ebf745... background: refactor cc-background-store
  ac26604... background: refactor cc-background-grid-item
  bec5b24... background: cache tumbnail for wallpaper gallery for a redr
  e22767b... background: changed variable names and small style changes
  007e701... background: cache slideshow-emblem icon
  19637d9... background: show only top border for gallery view
  dac02a9... background: adapt meson.build for file changes
  131cc9c... background: change description for open in File and open in
  edf69bd... background: use autoptr where possible
  81e1bf0... background: clean up files and code and remove build warnin