Fix build with directory-1.2.6.2.

It started exporting a isSymbolicLink which supports windows. But,
git-annex does no use symlinks on windows yet and this conflicts with the
function by the same name from unix-compat, so hide it.

Utility/Path.hs

@@ -12,7 +12,7 @@ module Utility.Path where
 
 import Data.String.Utils
 import System.FilePath
-import System.Directory
+import System.Directory hiding (isSymbolicLink)
 import Data.List
 import Data.Maybe
 import Data.Char