PGF library: expose only PGF and PGF.Internal instead of all modules

PGF exports the public, stable API.
PGF.Internal exports additional things needed in the GF compiler & shell,
including the nonstardard version of Data.Binary.

src/runtime/haskell-bind/PGF2.hsc

@@ -1,4 +1,13 @@
 {-# LANGUAGE ExistentialQuantification, DeriveDataTypeable #-}
+-------------------------------------------------
+-- |
+-- Maintainer  : Krasimir Angelov
+-- Stability   : stable
+-- Portability : portable
+--
+-- This is the Haskell binding to the C run-time system for
+-- loading and interpreting grammars compiled in Portable Grammar Format (PGF).
+-------------------------------------------------
 #include <pgf/pgf.h>
 #include <gu/enum.h>
 #include <gu/exn.h>

src/runtime/haskell/PGF/Internal.hs

@@ -0,0 +1,18 @@
+{-# OPTIONS_HADDOCK hide #-}
+-------------------------------------------------
+-- |
+-- Stability   : unstable
+--
+-------------------------------------------------
+module PGF.Internal(module Internal) where
+import PGF.Binary as Internal
+import PGF.Data as Internal
+import PGF.Macros as Internal
+import PGF.Optimize as Internal
+import PGF.Printer as Internal
+import PGF.Utilities as Internal
+
+import Data.Binary as Internal
+import Data.Binary.Get as Internal
+import Data.Binary.IEEE754 as Internal
+import Data.Binary.Put as Internal

src/runtime/haskell/PGF/Utilities.hs

@@ -3,10 +3,10 @@ module PGF.Utilities where
 import Data.Set(empty,member,insert)
 
 
--- | Like 'nub', but O(n log n) instead of O(n^2), since it uses a set to lookup previous things.
+-- | Like 'Data.List.nub', but O(n log n) instead of O(n^2), since it uses a set to lookup previous things.
 --   The result list is stable (the elements are returned in the order they occur), and lazy.
 --   Requires that the list elements can be compared by Ord.
---   Code ruthlessly taken from http://hpaste.org/54411
+--   Code ruthlessly taken from <http://hpaste.org/54411>
 nub' :: Ord a => [a] -> [a]
 nub' = loop empty
     where loop _    []            = []