OS X - maximize app's window from the Dock or using cmd-tab

On OS X it's possible to maximize app's window by clicking on an app's
icon in the Dock.
Another trick is to use cmd-tab to select an app +,
while still holding the 'cmd' key, press the 'option' key -
this should also maximize a window.
None of these works at the moment, and to enable these features app
delegate should return YES from the

-applicationShouldHandleRepopen:hasVisibleWindows:.

method.

Task-number: QTBUG-40084
Change-Id: I33ba9e74d55d41d23deb429612519b746d461d9e
Reviewed-by: Timur Pocheptsov <Timur.Pocheptsov@digia.com>
Reviewed-by: Morten Johan Sørvig <morten.sorvig@digia.com>
Reviewed-by: Laszlo Agocs <laszlo.agocs@digia.com>