[gtk] (7 commits) ...Merge branch 'wip/chergert/gdk-macos-for-master' into 'master'

[Matthias Clasen <matthiasc src gnome org>]

Summary of changes:

  9431c70... macos: freeze updates until surface is mapped (*)
  2e52386... macos: send focus-out event to windowing (*)
  e317b9b... macos: maintain GList element consistency (*)
  92f0216... macos: ensure element is part of queue (*)
  b68e0bb... muxer: add helper to get group by name (*)
  004f0a6... macos: plug leak of application windows (*)
  6ecae6c... Merge branch 'wip/chergert/gdk-macos-for-master' into 'mast

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