Revisit Bug 770 and Bug 771: Only use FLAG_IS_FULLSCREEN_SPAN if required; At MonitoMode change, reset fullscreen if FLAG_IS_FULLSCREEN_SPAN is supported.
- Bug 770: Only use FLAG_IS_FULLSCREEN_SPAN if required - If X11 WindowDriver _and_ virtual-screen-size > fullscreenViewport, - else we still use _NET_WM_STATE_FULLSCREEN on X11!
- Bug 771: At MonitoMode change, reset fullscreen if FLAG_IS_FULLSCREEN_SPAN is supported - Since we may still use _NET_WM_STATE_FULLSCREEN on X11: - Pause fullscreen at monitorModeChangeNotify(..) - Resume fullscreen at monitorModeChanged(..)