go.net: add PATENTS file to the subrepo.
go.net: add PATENTS file to the subrepo.

R=r
CC=golang-dev
http://codereview.appspot.com/5996045

fernandez14/go.net,polydawn-ports/go.net,ssor/go.net,gigq/go.net,andrewzeneski/go.net,go-mirrors/go.net