Import pretty-print from optparse

instead of depending on ansi-wl-pprint

src/GHCMod.hs

@@ -17,7 +17,6 @@ import Language.Haskell.GhcMod.Monad
 import System.FilePath ((</>))
 import System.Directory (setCurrentDirectory, getAppUserDataDirectory,
                         removeDirectoryRecursive)
--- import System.Environment (getArgs)
 import System.IO
 import System.Exit
 import Text.PrettyPrint hiding ((<>))

src/GHCMod/Options/DocUtils.hs

@@ -26,7 +26,7 @@ module GHCMod.Options.DocUtils (
 
 import Options.Applicative
 import Data.Monoid (Monoid) -- for ghc<7.10
-import Text.PrettyPrint.ANSI.Leijen as PP hiding ((<>), (<$>), (<$$>), int)
+import Options.Applicative.Help.Pretty as PP hiding ((<$$>), int)
 
 desc :: [Doc] -> InfoMod a
 desc = footerDoc . Just . indent 2 . vsep