Update QXbWindow orientation API

Update QXbWindow orientation API

After orientation handling was split in window orientation
and content orientation QXcbWindow remained with the old api.
This patch renames setOrientation to handleContentOrientationChange,
fixing the issue of double status bar (portrait and landscape)
when running Qt5 apps with QtComponents on N9 in portrait mode.
(thanks to Simon for pointing out the difference between
changing the window and the content orientations)

Change-Id: I20d0be0c7f7e4593ac1e3c2ac2518144fc7fed0e
Reviewed-by: Simon Hausmann <simon.hausmann@nokia.com>