[gnome-control-center] (20 commits) Non-fast-forward update to branch gbsneto/background

[Georges Basile Stavracas Neto <gbsneto src gnome org>]

The branch 'gbsneto/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:

  c2e308b... flatpak: Add gnome-backgrounds
  8f5083b... background: Rename ui file to cc-background-panel.ui
  e7a4a6d... background: Turn into a template class
  5ae4623... background: Make BgSource receive a GtkWidget
  57befff... background: Introduce CcBackgroundChooser
  46ac44a... background-panel: Remove background chooser buttons
  4f66c8a... background: Cache thumbnails in CcBackgroundItem
  521ce1f... background: Switch to GtkFlowBox
  01868ed... background: Remove CcBackgroundChooserDialog
  f1bb3ce... background: Use the cairo_t provided by GTK
  0137bd5... background: Move preview to CcBackgroundPreview
  8325711... background: Use widgets to render slideshow emblem
  fcad5f7... background: Introduce BgRecentSource
  45c6907... background: Manage recent backgrounds

Commits added to the branch:

  6872c76... sound: Clean up labels of devices without origin (*)
  08c6418... Update French translation (*)
  86c7505... printers: Use correct type for print job id (*)
  21df888... printers: Do not notify about job edited by user (*)
  2b1f76f... printers: Revert previous 2 commits (*)
  8ecf2e0... flatpak: Add gnome-backgrounds
  8e87358... background: Rename ui file to cc-background-panel.ui
  3bebfe2... background: Turn into a template class
  8cdbb7b... background: Make BgSource receive a GtkWidget
  a200fc9... background: Introduce CcBackgroundChooser
  e40c7e7... background-panel: Remove background chooser buttons
  5e4495b... background: Cache thumbnails in CcBackgroundItem
  0f2424d... background: Switch to GtkFlowBox
  4b73a8e... background: Remove CcBackgroundChooserDialog
  74eed4f... background: Use the cairo_t provided by GTK
  0d7c5ea... background: Move preview to CcBackgroundPreview
  041540f... background: Use widgets to render slideshow emblem
  bcf7b45... background: Introduce BgRecentSource
  fd4dc52... background: Manage recent backgrounds
  1863eef... background: Remove dead code

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