Correct placement of window event flush for window state

A bad cherry-pick meant that 155363 put some code window flushing code
inside the wrong function. This fixes where the flush should occur.

Change-Id: I468d9881d08c358cf559a12d52b18702db3cb1e0
Reviewed-by: Andy Nichols <andy.nichols@digia.com>
Fix Qt key extension loading

A typo in QWaylandDisplay meant that the Qt key extension was not being
registered in the client.

Change-Id: I5f276beed41502cb90d4090e553415275ee5a804
Reviewed-by: Jan Arne Petersen <jan.petersen@kdab.com>
Reviewed-by: Andy Nichols <andy.nichols@digia.com>