codereview: repeated hg mail sends "PTAL"
codereview: repeated hg mail sends "PTAL"

also send out hg mail for TBR submits

R=r
CC=golang-dev
http://codereview.appspot.com/183137

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