[gtk] (7 commits) Non-fast-forward update to branch wip/matthiasc/popup5

[Matthias Clasen <matthiasc src gnome org>]

The branch 'wip/matthiasc/popup5' 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:

  f66bfc5... Stop using gtk_widget_get_surface
  a1cef43... Drop gtk_widget_get_surface
  7968242... Mention gtk_widget_get_surface in the migration guide
  7048d73... Stop using gtk_widget_is_toplevel
  aadac6f... Stop using gtk_widget_is_toplevel
  472f06e... Drop gtk_widget_is_toplevel
  babab6a... Mention gtk_widget_is_toplevel in the migration guide

Commits added to the branch:

  880166e... Stop using gtk_widget_get_surface
  ee736eb... Drop gtk_widget_get_surface
  903af66... Mention gtk_widget_get_surface in the migration guide
  d53a02f... Stop using gtk_widget_is_toplevel
  172f763... Drop gtk_widget_is_toplevel
  e0fbdce... Mention gtk_widget_is_toplevel in the migration guide
  bea83d8... Cosmetics