fix for fullscreen on X11 (used by the BGE, not blender application),

changing the screen resolution wasn't still allowed for larger virtual desktops.

added an exclusive option to ghost so the fullscreen window is ignored by the window manager and we get all events. (common practice for games on X11).

source/gameengine/GamePlayer/ghost/GPG_Application.cpp

@@ -386,6 +386,7 @@ bool GPG_Application::startFullScreen(
 
 	fSystem->beginFullScreen(setting, &m_mainWindow, stereoVisual, samples);
 	m_mainWindow->setCursorVisibility(false);
+	/* note that X11 ignores this (it uses a window internally for fullscreen) */
 	m_mainWindow->setState(GHOST_kWindowStateFullScreen);
 
 	success = initEngine(m_mainWindow, stereoMode);