test: rewrite test/run shell script + errchk (perl) in Go
test: rewrite test/run shell script + errchk (perl) in Go

This doesn't run all ~750 of the tests, but most.

Progress on issue 2833

R=golang-dev, ality, rsc, r, r
CC=golang-dev
http://codereview.appspot.com/5625044

tav/go,tav/go,tav/go,tav/go,tav/go,tav/go,tav/go