stop cached ssh connection w/o needing to look up host and port

Turns out that with -O stop -S socketfile, ssh does not need the real
hostname, or port to be specificed. This is because it simply talks to the
ssh behind the socket and tells it to stop. So, can eliminate the
conversion back from a socketfile to host and port. Which will allow using
shorter filenames for sockets in the future.

Annex/Ssh.hs

@@ -51,17 +51,18 @@ sshInfo (host, port) = go =<< sshCacheDir
 	go (Just dir) = do
 		let socketfile = dir </> hostport2socket host port
 		if valid_unix_socket_path socketfile
-			then return (Just socketfile, cacheparams socketfile)
+			then return (Just socketfile, sshConnectionCachingParams socketfile)
 			else do
 				socketfile' <- liftIO $ relPathCwdToFile socketfile
 				if valid_unix_socket_path socketfile'
-					then return (Just socketfile', cacheparams socketfile')
+					then return (Just socketfile', sshConnectionCachingParams socketfile')
 					else return (Nothing, [])
-	cacheparams :: FilePath -> [CommandParam]
-	cacheparams socketfile =
-		[ Param "-S", Param socketfile
-		, Params "-o ControlMaster=auto -o ControlPersist=yes"
-		]
+
+sshConnectionCachingParams :: FilePath -> [CommandParam]
+sshConnectionCachingParams socketfile = 
+	[ Param "-S", Param socketfile
+	, Params "-o ControlMaster=auto -o ControlPersist=yes"
+	]
 
 {- ssh connection caching creates sockets, so will not work on a
  - crippled filesystem. A GIT_ANNEX_TMP_DIR can be provided to use
@@ -116,14 +117,13 @@ sshCleanup = go =<< sshCacheDir
 		stopssh socketfile
 #endif
 	stopssh socketfile = do
-		let (host, port) = socket2hostport socketfile
-		(_, params) <- sshInfo (host, port)
+		let params = sshConnectionCachingParams socketfile
 		-- "ssh -O stop" is noisy on stderr even with -q
 		void $ liftIO $ catchMaybeIO $
 			withQuietOutput createProcessSuccess $
 				proc "ssh" $ toCommand $
 					[ Params "-O stop"
-					] ++ params ++ [Param host]
+					] ++ params ++ [Param "any"]
 		-- Cannot remove the lock file; other processes may
 		-- be waiting on our exclusive lock to use it.
 
@@ -131,13 +131,6 @@ hostport2socket :: String -> Maybe Integer -> FilePath
 hostport2socket host Nothing = host
 hostport2socket host (Just port) = host ++ "!" ++ show port
 
-socket2hostport :: FilePath -> (String, Maybe Integer)
-socket2hostport socket
-	| null p = (h, Nothing)
-	| otherwise = (h, readish p)
-  where
-	(h, p) = separate (== '!') $ takeFileName socket
-
 socket2lock :: FilePath -> FilePath
 socket2lock socket = socket ++ lockExt