Reorganize module namespace

- Remove Language.Haskell prefix from all modules
- Move 'GHCMod.*' to 'GhcMod.Exe'
- Move 'GhcModExe' to 'GhcMod.Exe'

core/GhcMod/Doc.hs

@@ -0,0 +1,20 @@
+module GhcMod.Doc where
+
+import GHC
+import GhcMod.Gap (withStyle, showDocWith)
+import Outputable
+import Pretty (Mode(..))
+
+showPage :: DynFlags -> PprStyle -> SDoc -> String
+showPage dflag style = showDocWith dflag PageMode . withStyle dflag style
+
+showOneLine :: DynFlags -> PprStyle -> SDoc -> String
+showOneLine dflag style = showDocWith dflag OneLineMode . withStyle dflag style
+
+getStyle :: GhcMonad m => m PprStyle
+getStyle = do
+    unqual <- getPrintUnqual
+    return $ mkUserStyle unqual AllTheWay
+
+styleUnqualified :: PprStyle
+styleUnqualified = mkUserStyle neverQualify AllTheWay