CONTRIBUTORS: add Gaal Yahas (Google CLA)
CONTRIBUTORS: add Gaal Yahas (Google CLA)

R=golang-dev, rsc
CC=golang-dev
https://codereview.appspot.com/7311053
abustany/go,abustany/go,abustany/go,abustany/go,abustany/go,abustany/go,abustany/go