add newtypes for QuickCheck to avoid LANG=C issues

All properties changed to use them, except for
prop_encode_c_decode_c_roundtrip, which already filtered to ascii
for other reasons.

A few modules had to be split out, because Setup does not build-depend
on QuickCheck.

Annex/View/ViewedFile.hs

@@ -17,6 +17,7 @@ module Annex.View.ViewedFile (
 ) where
 
 import Annex.Common
+import Utility.QuickCheck
 
 import qualified Data.ByteString as S
 
@@ -78,11 +79,12 @@ dirFromViewedFile = joinPath . drop 1 . sep [] ""
 			[] -> sep l curr cs
 		| otherwise = sep l (c:curr) cs
 
-prop_viewedFile_roundtrips :: FilePath -> Bool
-prop_viewedFile_roundtrips f
+prop_viewedFile_roundtrips :: TestableFilePath -> Bool
+prop_viewedFile_roundtrips tf
 	-- Relative filenames wanted, not directories.
 	| any (isPathSeparator) (end f ++ beginning f) = True
 	| isAbsolute f = True
 	| otherwise = dir == dirFromViewedFile (viewedFileFromReference f)
   where
+	f = fromTestableFilePath tf
 	dir = joinPath $ beginning $ splitDirectories f