C: add Chris Manghane (Google CLA)

R=golang-dev
CC=golang-dev
https://codereview.appspot.com/12222043
misc/dashboard/app, misc/dashboard/builder: delete from main repo; part of move to go.tools
See also https://codereview.appspot.com/12180043/

R=adg
CC=golang-dev
https://codereview.appspot.com/12213043

Committer: Andrew Gerrand <adg@golang.org>