Socks client support

I've basically made some simple changes that permit VX Connectbot to connect to SOCKS5 proxies. It uses the HTTP proxy configuration portion when you edit the host, and putting in a URL like socks5://my.socks.server:1080 (pre-patch this only permits HTTP proxies), you can use a SOCKS5 proxy to connect. I've used this to good effect connecting to some personal Tor hidden services with the help of Orbot. (socks5://127.0.0.1:9050 suffices for this).

I've needed to merge some of the jsocks upstream code in order to get this to work, and made a few changes to the trilead SSH code to make it use a SocksSocket instead of a plain socket, and to use SOCKS-based DNS resolution rather than local DNS.

This feature obviously requires a bit of cleanup before it's ready, but it's a start I think.