expose Control.Monad.join

I think I've been looking for that function for some time.
Ie, I remember wanting to collapse Just Nothing to Nothing.

Utility/Rsync.hs

@@ -22,7 +22,7 @@ rsyncShell command = [Param "-e", Param $ unwords $ map escape (toCommand comman
 	{- rsync requires some weird, non-shell like quoting in
 	- here. A doubled single quote inside the single quoted
 	- string is a single quote. -}
-	escape s = "'" ++  join "''" (split "'" s) ++ "'"
+	escape s = "'" ++  intercalate "''" (split "'" s) ++ "'"
 
 {- Runs rsync in server mode to send a file. -}
 rsyncServerSend :: [CommandParam] -> FilePath -> IO Bool