New module: XMonad.Prelude

This is a convenience module in order to have less import noise.  It
re-exports the following:

  a) Commonly used modules in full (Data.Foldable, Data.Applicative, and
     so on); though only those that play nicely with each other, so that
     XMonad.Prelude can be imported unqualified without any problems.
     This prevents things like `Prelude.(.)` and `Control.Category.(.)`
     fighting with each other.

  b) Helper functions that don't necessarily fit in any other module;
     e.g., the often used abbreviation `fi = fromIntegral`.

XMonad/Layout/IfMax.hs

@@ -8,7 +8,7 @@
 -- Stability   :  unstable
 -- Portability :  unportable
 --
--- Provides IfMax layout, which will run one layout if there are maximum N 
+-- Provides IfMax layout, which will run one layout if there are maximum N
 -- windows on workspace, and another layout, when number of windows is greater
 -- than N.
 --
@@ -23,16 +23,16 @@ module XMonad.Layout.IfMax
     , ifMax
     ) where
 
-import Control.Arrow
+import Control.Arrow ((&&&))
 import qualified Data.List as L
 import qualified Data.Map  as M
-import Data.Maybe
 
 import XMonad
+import XMonad.Prelude
 import qualified XMonad.StackSet as W
 
 -- $usage
--- IfMax layout will run one layout if number of windows on workspace is as 
+-- IfMax layout will run one layout if number of windows on workspace is as
 -- maximum N, and else will run another layout.
 --
 -- You can use this module by adding folowing in your @xmonad.hs@:
@@ -91,4 +91,3 @@ ifMax :: (LayoutClass l1 w, LayoutClass l2 w)
       -> l2 w           -- ^ Second layout
       -> IfMax l1 l2 w
 ifMax n l1 l2 = IfMax n l1 l2
-