~/.xmonad: Adopt for newer ghc libraries.

.xmonad/xmonad.hs

import System.IO (hPutStrLn)
import Data.IORef.MonadIO (newIORef, readIORef, modifyIORef)
import Monad (when)
import Control.Monad (when)
import Data.Monoid (All (All))
import qualified XMonad.StackSet as W