Declare a few modules as Safe rather than Trustworthy.

This silences a GHC 7.10 warning that indicates that these modules are
marked trustworthy when in fact they don't need to, since they are safe.

src/Data/Binary/Class.hs

 {-# LANGUAGE CPP, FlexibleContexts #-}
 #if __GLASGOW_HASKELL__ >= 701
-{-# LANGUAGE Trustworthy #-}
+{-# LANGUAGE Safe #-}
 #endif
 #ifdef GENERICS
 {-# LANGUAGE DefaultSignatures #-}
@@ -41,12 +41,13 @@ module Data.Binary.Class (
     ) where
 
 import Data.Word
+import Data.Bits
+import Data.Int
 
 import Data.Binary.Put
 import Data.Binary.Get
 
 import Control.Monad
-import Foreign
 
 import Data.ByteString.Lazy (ByteString)
 import qualified Data.ByteString.Lazy as L

src/Data/Binary/Generic.hs

 {-# LANGUAGE BangPatterns, CPP, FlexibleInstances, KindSignatures,
-    ScopedTypeVariables, Trustworthy, TypeOperators, TypeSynonymInstances #-}
+    ScopedTypeVariables, Safe, TypeOperators, TypeSynonymInstances #-}
 {-# OPTIONS_GHC -fno-warn-orphans #-}
 
 -----------------------------------------------------------------------------

src/Data/Binary/Put.hs

 {-# LANGUAGE CPP #-}
 #if __GLASGOW_HASKELL__ >= 701
-{-# LANGUAGE Trustworthy #-}
+{-# LANGUAGE Safe #-}
 #endif
 
 -----------------------------------------------------------------------------