[xmonad] darcs patch: X.H.UrgencyHook: performance fix

Sat Mar 27 21:15:03 CET 2010 Tomas Janousek * X.H.UrgencyHook: performance fix cleanupUrgents would update the Map in extensible state 2-times the number of visible windows, resulting in excessive memory usage and garbage collection. This seems to make it behave correctly. Note: this is actually not necessary after the fix to core I just posted, but it should speed things up a little if one has hundreds of visible windows. -- Tomáš Janoušek, a.k.a. Liskni_si, http://work.lisk.in/