[gtk+/quartz-integration] (13 commits) ...Merge branch 'master' into quartz-integration

[John Ralls <jralls src gnome org>]

Summary of changes:

  89eb869... Avoid crashes calling gdk_window_enable_synchronized_config (*)
  cbd313c... correcting on off in gtkswitch according to bugreport:63823 (*)
  eaca2ea... [l10n] Updated Estonian translation (*)
  66593ef... Added warnings to GtkCellLayout when api is accessed and th (*)
  04494c5... Making GtkCellLayout "no cell area yet" warning a g_critica (*)
  7e29fc5... gtkshow: don't call _get_display() on a NULL GdkScreen (*)
  df78c9e... Add some doc details (*)
  9d85d87... Move GtkMenuBar docs inline (*)
  b23839c... Add an example for custom css (*)
  04248fb... Update some outdated content in the question index (*)
  985b0e5... Add a migration guide section about multiple backends (*)
  92c8a3e... Remove an overlooked instance of gdk drawing api (*)
  f9b0206... Merge branch 'master' into quartz-integration

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