[gtk] (12 commits) ...Merge branch 'matthiasc-for-master' into 'master'

[Matthias Clasen <matthiasc src gnome org>]

Summary of changes:

  d2a794b... menu tracker item: Improve logging (*)
  db7f018... action muxer: Add some convenience api (*)
  3b565d7... action muxer: cosmetics (*)
  00c828e... inspector: Redo the action page (*)
  44970b5... inspector: Fix actionable handling (*)
  d2e0d32... widget: Cosmetics (*)
  9bb2d1e... widget: Remove gtk_widget_list_action_prefixes (*)
  72d306c... entry: Remove hacky code (*)
  8209299... file chooser: Stop using gtk_widget_get_action_group (*)
  bc56860... places sidebar: Stop using gtk_widget_get_action_group (*)
  cc66792... Drop gtk_widget_get_action_group (*)
  75713a9... Merge branch 'matthiasc-for-master' into 'master'

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