iOS: StatusBar should be painted by a QML control, not in C++ (in default project too)

Some standard iOS animations have to involve status bar area (usually something has to fly under it), it is a problem if status bar is painted in C++ out of the area available to ApplicationWindow in QML.

Reported as @vestbo ( Tor Arne Vestbø ) request based on https://github.com/amarchen/CuteContacts-iOS/issues/2