Instead of checking for window state and giving it extra styles that
fit, just give it all styles that it is missing. It turned out that
otherwise it is impossible to, for example, restore a maximized window
via sysmenu. Also, be more flexible towards GDK/WM window state mismatches
and consider the window minimized/maximized if *either* GDK or WM thinks so.

https://bugzilla.gnome.org/show_bug.cgi?id=776485