Missing window properties

Window properties got missing between moment of window creation and registration to the compositor.

This is tested on Qt5.9 and the actual window property events can be seen with WAYLAND_DEBUG=1.

The problem is inside the application-manager. As there is a short timeframe, between when the ExtendedSurface (which is needed for the window properties) and when setupWindow() is called, which connects the signal from the extendesurface, to the actual WindowManager signal. The setupWindow() function is called once the shellsurface is created and it hasContent to display. Every windowproperty change between the creation of the extendedsurface and the shellsurface::hasContent event are lost.