[gtk] (4 commits) Non-fast-forward update to branch x11-props

[Matthias Clasen <matthiasc src gnome org>]

The branch 'x11-props' 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:

  7ee45f0... Drop GdkToplevel:sticky
  5624005... tests: Stop using keep above/below
  5d8e7be... window: Drop keep above/below
  e71a096... Drop GdkToplevel:keep-above/below

Commits added to the branch:

  b18882f... Drop GdkToplevel:sticky
  e6ca875... tests: Stop using keep above/below
  f5bd709... window: Drop keep above/below
  ea06f5d... Drop GdkToplevel:keep-above/below