more partial function removal

Left a few Prelude.head's in where it was checked not null and too hard to
remove, etc.

Git/CheckAttr.hs

@@ -36,10 +36,9 @@ lookup attr files repo = do
 				, Param attr
 				, Params "-z --stdin"
 				] repo
-		topair l = (file, value)
+		topair l = (Git.Filename.decode file, value)
 			where 
-				file = Git.Filename.decode $ join sep $ take end bits
-				value = bits !! end
-				end = length bits - 1
+				file = join sep $ beginning bits
+				value = end bits !! 0
 				bits = split sep l
 				sep = ": " ++ attr ++ ": "

Git/UnionMerge.hs

@@ -134,7 +134,7 @@ hashObject repo content = getSha subcmd $ do
 calcMerge :: [(Ref, [L.ByteString])] -> Either Ref [L.ByteString]
 calcMerge shacontents
 	| null reuseable = Right $ new
-	| otherwise = Left $ fst $ head reuseable
+	| otherwise = Left $ fst $ Prelude.head reuseable
 	where
 		reuseable = filter (\c -> sorteduniq (snd c) == new) shacontents
 		new = sorteduniq $ concat $ map snd shacontents