codereview: add submit message support for newer clone URL and subrepos
codereview: add submit message support for newer clone URL and subrepos

R=golang-dev, rsc
CC=golang-dev
http://codereview.appspot.com/5689063

Committer: Russ Cox <5ad239cb8a44f659eaaee0aa1ea5b94947abe557@golang.org>

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