NSWindowStyleMaskNonactivatingPanel is almost exactly the same behavior
as WS_EX_NOACTIVATE on Windows: it prevents the window from activating
the app, but does not prevent it from being focused if the app is
already active.
Signed-off-by: Tim Clem <tclem@codeweavers.com>
Signed-off-by: Alexandre Julliard <julliard@winehq.org>