New regression test: dynamic forwarding

[Dan Kaminsky]

>on openbsd netcat could be used, it supports both socks 4 and 5.
>
>_______________________________________________
>openssh-unix-dev mailing list
>openssh-unix-dev at mindrot.org
>http://www.mindrot.org/mailman/listinfo/openssh-unix-dev
>  
>
Given that we already have a good portion of the necessary code to 
support simple SOCKS already, _and_ that a built-in client would then be 
able to interface with our already built-in server, why _not_ support an 
ultra-simple socks4/socks5 client mode?

I mean, we already have the struct declaration, and it's only a few 
bytes in front of the TCP session...surely for such a simple case it's 
better to integrate than ask the user to route their SSH session through 
a probably insecure proxycommand?

If nothing else, it'd help regression testing.

--Dan