[xmonad] darcs patch: change screen by clicking on an empty screen

Hi, this is the analogue to my prevoius patch, this time for those with focuseFollowsMouse = False. Greetings, Joachim Wed Oct 8 18:45:06 CEST 2008 Joachim Breitner * change screen by clicking on an empty screen by adding the buttonPressMask to the root window, and making sure focus is run even when the user clicks on the root window.