e17/comp: sniff some property events from override redirect windows and support _NET_WM_WINDOW_OPACITY
e17/comp: sniff some property events from override redirect windows and support _NET_WM_WINDOW_OPACITY

no more opaque black background for gksu


git-svn-id: 6ac5796aeae0cef97fb47bcc287d4ce899c6fa6e@57805 7cbeb6ba-43b4-40fd-8cce-4c39aea84d33

jordemort/e17,jordemort/e17,jordemort/e17