Ignore cloned screens
Ignore cloned screens

This patch ignores screens that are just clones of existing ones,
or are completely contained in another. Currently only for rescreen, not yet for
xmonad start.

darcs-hash:20071231180628-23c07-9c55cedfc5e1e22d1bddaae13c296900558e8849

Happy-Ferret/xmonad