[xmonad] mouse resize now available

Hi, I've just pushed a few patches that introduce the new XMonad.Actions.MouseResize module, which is a layout modifier to be used together with WindowArrager to resize windows by grabbing the window's lower right corner. With this feature, which can be obviously extended (mouse resize by grabbing the borders?) I think that the new decoration framework is complete. I added the mouse resize modifier to SimpleFloat and to the resizable layouts you can find in DecorationMadness. What remains to be done is solving the problematic interactions between decorations and WindowNavigation. No other major bug has been reported so far (but I'm waiting...;). Hope you'll enjoy. Andrea