Add some more comments on the 'focused' window state.
Add some more comments on the 'focused' window state.

--HG--
branch : gui_navigation-devel

cbeck88/cegui-mirror-two,cbeck88/cegui-mirror-two,cbeck88/cegui-mirror-two,cbeck88/cegui-mirror-two,cbeck88/cegui-mirror-two