convert TopFilePath to use RawFilePath

Adds a dependency on filepath-bytestring, an as yet unreleased fork of
filepath that operates on RawFilePath.

Git.Repo also changed to use RawFilePath for the path to the repo.

This does eliminate some RawFilePath -> FilePath -> RawFilePath
conversions. And filepath-bytestring's </> is probably faster.
But I don't expect a major performance improvement from this.
This is mostly groundwork for making Annex.Location use RawFilePath,
which will allow for a conversion-free pipleline.

Remote/Bup.hs

@@ -230,7 +230,7 @@ onBupRemote r runner command params = do
 	(sshcmd, sshparams) <- Ssh.toRepo NoConsumeStdin r c remotecmd
 	liftIO $ runner sshcmd sshparams
   where
-	path = Git.repoPath r
+	path = fromRawFilePath $ Git.repoPath r
 	base = fromMaybe path (stripPrefix "/~/" path)
 	dir = shellEscape base
 

Remote/External.hs

@@ -409,7 +409,8 @@ handleRequest' st external req mp responsehandler
 		send $ CREDS (fst creds) (snd creds)
 	handleRemoteRequest GETUUID = send $
 		VALUE $ fromUUID $ externalUUID external
-	handleRemoteRequest GETGITDIR = send . VALUE =<< fromRepo Git.localGitDir
+	handleRemoteRequest GETGITDIR = 
+		send . VALUE . fromRawFilePath =<< fromRepo Git.localGitDir
 	handleRemoteRequest (SETWANTED expr) =
 		preferredContentSet (externalUUID external) expr
 	handleRemoteRequest GETWANTED = do

Remote/Git.hs

@@ -680,8 +680,8 @@ fsckOnRemote r params
 		r' <- Git.Config.read r
 		environ <- getEnvironment
 		let environ' = addEntries 
-			[ ("GIT_WORK_TREE", Git.repoPath r')
-			, ("GIT_DIR", Git.localGitDir r')
+			[ ("GIT_WORK_TREE", fromRawFilePath $ Git.repoPath r')
+			, ("GIT_DIR", fromRawFilePath $ Git.localGitDir r')
 			] environ
 		batchCommandEnv program (Param "fsck" : params) (Just environ')
 

Remote/Helper/Git.hs

@@ -20,7 +20,7 @@ repoCheap = not . Git.repoIsUrl
 localpathCalc :: Git.Repo -> Maybe FilePath
 localpathCalc r
 	| availabilityCalc r == GloballyAvailable = Nothing
-	| otherwise = Just $ Git.repoPath r
+	| otherwise = Just $ fromRawFilePath $ Git.repoPath r
 
 availabilityCalc :: Git.Repo -> Availability
 availabilityCalc r
@@ -36,7 +36,7 @@ guardUsable r fallback a
 
 gitRepoInfo :: Remote -> Annex [(String, String)]
 gitRepoInfo r = do
-	d <- fromRepo Git.localGitDir
+	d <- fromRawFilePath <$> fromRepo Git.localGitDir
 	mtimes <- liftIO $ mapM (modificationTime <$$> getFileStatus)
 		=<< dirContentsRecursive (d </> "refs" </> "remotes" </> Remote.name r)
 	let lastsynctime = case mtimes of

Remote/Helper/Ssh.hs

@@ -65,7 +65,7 @@ git_annex_shell cs r command params fields
 		let params' = if debug
 			then Param "--debug" : params
 			else params
-		return (Param command : File dir : params')
+		return (Param command : File (fromRawFilePath dir) : params')
 	uuidcheck NoUUID = []
 	uuidcheck u@(UUID _) = ["--uuid", fromUUID u]
 	fieldopts