[gtk] (7 commits) Non-fast-forward update to branch wip/matthiasc/focus2

[Matthias Clasen <matthiasc src gnome org>]

The branch 'wip/matthiasc/focus2' 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:

  ea88945... widget: Add a next-focus-child API
  288c99f... stack: Implement next_focus_child

Commits added to the branch:

  0412059... widget: Add a next-focus-child API
  15d71d1... stack: Implement next_focus_child
  6d5adb4... expander: remove the ::focus implementation
  0c17a70... inspector: Add a focus overlay
  71d0add... window: Make focus wrap again
  f519c36... Exclude non-drawable widgets from focus
  a6b53bc... Remove gtk_widget_focus_move