Add ui/hideMenuBar boolean option, defaulting to on, which hides the
main menubar when the mouse is idle or outside the frame.
This is disabled on mac, because on macs the main menubar is not part of
the application window.
Fix pointer hiding/unhiding by connecting panel events to the gamearea
mouse event handler.
Clean up the pausing when menus are opened code, make it actually work
on Windows.
Signed-off-by: Rafael Kitover <rkitover@gmail.com>
504ca08b6b