D18365: Add a flag to keep a window on top

[Aleix Pol Gonzalez]

apol added a comment.


  (Catching up with e-mail) did this fall through?

REPOSITORY
  R127 KWayland

REVISION DETAIL
  https://phabricator.kde.org/D18365

To: davidedmundson, #kwin
Cc: apol, zzag, kde-frameworks-devel, michaelh, ngraham, bruns