exp/ssh: add simple tcpip.go functional tests
exp/ssh: add simple tcpip.go functional tests

R=rsc, agl, n13m3y3r, bradfitz
CC=golang-dev
http://codereview.appspot.com/5385041

Committer: Adam Langley <db68fba232b2c49ed3e9d3081df349dde7b61dfd@golang.org>

gnanderson/go,tv42/old-go,gnanderson/go,dsriram/golang,tv42/old-go,apparentlymart/golang,pombredanne/go-deleteme,apparentlymart/golang,pombredanne/go-deleteme,apparentlymart/golang,dsriram/golang,dsriram/golang,pombredanne/go-deleteme,tv42/old-go,apparentlymart/golang,gnanderson/go,pombredanne/go-deleteme,gnanderson/go,tv42/old-go,tv42/old-go,gnanderson/go,apparentlymart/golang,dsriram/golang,dsriram/golang,tv42/old-go,pombredanne/go-deleteme,dsriram/golang,gnanderson/go,apparentlymart/golang,gnanderson/go,pombredanne/go-deleteme,apparentlymart/golang,pombredanne/go-deleteme,dsriram/golang,tv42/old-go