Windows: Fix bug where windows stopped painting after a restore.

This is an improvement over 6800728d where we only fixed it if
the window was in "normal" state (Qt::WindowNoState) before
minimizing.

With this patch, if the window was previously maximized or
full-screen it will also get the expose events when being
restored.

Change-Id: I4a30423145e0999c5d0a5ee2a989730b83f4e3f2
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@digia.com>
Reviewed-by: Nicolas Arnaud-Cormos <nicolas@kdab.com>