Avoid excessive escaping for rsync special remotes that are not accessed over ssh.

This is actually tricky, 45bbf210a1 added
the escaping because it's needed for rsync that does go over ssh.
So I had to detect whether the remote's rsync url will use ssh or not,
and vary the escaping.

doc/bugs/extraneous_shell_escaping_for_rsync_remotes.mdwn

@@ -11,3 +11,5 @@ I attached a patch for this.
 > 
 > Ah, you're not using rsync over ssh, but just to a local directory,
 > right? --[[Joey]]
+
+>> [[fixed|done]] --[[Joey]]