wip RawFilePath

Goal is to make git-annex faster by using ByteString for all the
worktree traversal. For now, this is focusing on Command.Find,
in order to benchmark how much it helps. (All other commands are
temporarily disabled)

Currently in a very bad unbuildable in-between state.

Git/Construct.hs

@@ -58,7 +58,7 @@ fromPath dir = fromAbsPath =<< absPath dir
  - specified. -}
 fromAbsPath :: FilePath -> IO Repo
 fromAbsPath dir
-	| absoluteGitPath dir = hunt
+	| absoluteGitPath (encodeBS dir) = hunt
 	| otherwise =
 		error $ "internal error, " ++ dir ++ " is not absolute"
   where