[gtk] (21 commits) Non-fast-forward update to branch wip/chergert/switcher-orientable

[Christian Hergert <chergert src gnome org>]

The branch 'wip/chergert/switcher-orientable' 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:

  fda1833... stackswitcher: implement GtkOrientable

Commits added to the branch:

  3aa34c1... gtkapplication-dbus: Fetch inital screen saver state async (*)
  f729912... Merge branch 'wip/chergert/fix-3977' into 'master' (*)
  0268c9d... Add tests for text buffer history (*)
  994a38c... textbuffer: Improve the docs (*)
  ffbfafb... textbuffer: Add some docs for undo (*)
  4b5f8e6... Merge branch 'test-text-buffer-undo' into 'master' (*)
  8ebdd25... docs: fix broken links (*)
  d0e29cc... Merge branch 'bilelmoussaoui/for-gi-docgen' into 'master' (*)
  90a829f... docs: fix gtk grid formatting (*)
  4362f7e... Merge branch 'bilelmoussaoui/for-gi-docgen-grid' into 'mast (*)
  9f93883... text: Propagate xalign to the placeholder (*)
  c9785c4... Merge branch 'placeholder-alignment' into 'master' (*)
  44bc9a2... Update Friulian translation (*)
  d1a7a55... box: Avoid redundant storage (*)
  b85b4f2... Merge branch 'box-orientation' into 'master' (*)
  44f07f7... texthistory: fix has_actionable function (*)
  c92b21b... Merge branch 'fix-has-actionable-function' into 'master' (*)
  c137f40... Merge branch 'screensaver-async-4' into 'master' (*)
  9c79b8b... invalid cast from 'GtkButton' to 'GtkBox' (*)
  7d3c3cb... Merge branch 'fix_cast_warning_adding_notebook_page' into ' (*)
  c848a51... stackswitcher: implement GtkOrientable

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