[xmonad] darcs patch: add configurable X Event handling (and 2 more)

Amended with an eventHook -> eventHooks change. Sun Nov 11 17:46:16 EST 2007 Devin Mullins * add configurable X Event handling Once this is committed, I'll port UrgencyHook to be an eventHook. I'm already in love, though: , eventHook = noFollow noFollow CrossingEvent {} = return False noFollow _ = return True Sun Nov 11 19:48:50 EST 2007 Devin Mullins * fix processEvent for droundy's existential change Mon Nov 12 02:34:07 EST 2007 Devin Mullins * change eventHook to eventHooks This way, composition is as simple as (:), and the general contract of filter chain halting is enforced by the definition of processEvent.