Qml Viewer runtime.activeWindow functionality should be available for standalone QML applications

QML Viewer provides runtime.activeWindow context property for QML applications for stopping and pausing animations, timers, active processing to save device battery when application window is not active (screensaver or keylock is active, the application is not the foreground application, the screen backlight is turned off). Energy efficiency is extremely important for mobile applications. QML Viewer is not an deployment tool however, so the activeWindow property is not available for most real-world mobile QML applications. As far as I know that kind of information is not exposed by any of the Qt Mobility APIs like System Info module.