[gtk+] (6 commits) Non-fast-forward update to branch wip/paint-stack-cleanup

[Jasper St. Pierre <jstpierre src gnome org>]

The branch 'wip/paint-stack-cleanup' 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:

  c1e5626... gdkwindow: Deprecate gdk_window_flush
  f3891d2... gtkwidget: Widgets are now always double-buffered
  e15cfba... gdkwindow: Remove the internal cairo_surface used for out-o

Commits added to the branch:

  5925f9e... GtkStatusbar: Add some space between the frame and the labe (*)
  b4d12ff... GtkIconCache: Add api to find if directories are empty (*)
  5ddacf0... GtkIconTheme: Don't create empty IconThemeDir structs (*)
  a26c2f8... gdkwindow: Deprecate gdk_window_flush
  74cd5a8... gtkwidget: Widgets are now always double-buffered
  b991474... gdkwindow: Remove the internal cairo_surface used for out-o

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