Clean up LANGUAGE pragmas

Make it git-friendly and drop some extra ones as suggested by hlint.

src/XMonad/Core.hs

@@ -1,6 +1,10 @@
-{-# LANGUAGE ExistentialQuantification, FlexibleInstances, GeneralizedNewtypeDeriving,
+{-# LANGUAGE DeriveTraversable #-}
-             MultiParamTypeClasses, TypeSynonymInstances, DeriveDataTypeable,
+{-# LANGUAGE ExistentialQuantification #-}
-             LambdaCase, NamedFieldPuns, DeriveTraversable #-}
+{-# LANGUAGE FlexibleInstances #-}
+{-# LANGUAGE GeneralizedNewtypeDeriving #-}
+{-# LANGUAGE LambdaCase #-}
+{-# LANGUAGE MultiParamTypeClasses #-}
+{-# LANGUAGE NamedFieldPuns #-}
 
 -----------------------------------------------------------------------------
 -- |

src/XMonad/Layout.hs

@@ -1,4 +1,6 @@
-{-# LANGUAGE FlexibleInstances, MultiParamTypeClasses, PatternGuards, TypeSynonymInstances, DeriveDataTypeable, LambdaCase, MultiWayIf #-}
+{-# LANGUAGE FlexibleInstances #-}
+{-# LANGUAGE MultiParamTypeClasses #-}
+{-# LANGUAGE PatternGuards #-}
 
 -- --------------------------------------------------------------------------
 -- |

src/XMonad/Main.hs

@@ -1,4 +1,6 @@
-{-# LANGUAGE MultiParamTypeClasses, FlexibleContexts, NamedFieldPuns #-}
+{-# LANGUAGE FlexibleContexts #-}
+{-# LANGUAGE MultiParamTypeClasses #-}
+
 ----------------------------------------------------------------------------
 -- |
 -- Module      :  XMonad.Main

src/XMonad/ManageHook.hs

@@ -1,5 +1,3 @@
-{-# LANGUAGE GeneralizedNewtypeDeriving #-}
-
 -----------------------------------------------------------------------------
 -- |
 -- Module      :  XMonad.ManageHook
@@ -8,7 +6,6 @@
 --
 -- Maintainer  :  spencerjanssen@gmail.com
 -- Stability   :  unstable
--- Portability :  not portable, uses cunning newtype deriving
 --
 -- An EDSL for ManageHooks
 --

src/XMonad/Operations.hs

@@ -1,4 +1,9 @@
-{-# LANGUAGE FlexibleContexts, FlexibleInstances, MultiParamTypeClasses, PatternGuards, LambdaCase #-}
+{-# LANGUAGE FlexibleContexts #-}
+{-# LANGUAGE FlexibleInstances #-}
+{-# LANGUAGE LambdaCase #-}
+{-# LANGUAGE MultiParamTypeClasses #-}
+{-# LANGUAGE PatternGuards #-}
+
 -- --------------------------------------------------------------------------
 -- |
 -- Module      :  XMonad.Operations