A+C: Josh Bleecher Snyder (individual CLA)

Generated by addca.

R=gobot
CC=golang-dev
https://codereview.appspot.com/12419043
html/template: handle nils during indirection

Fixes issue 5982.

R=golang-dev, r
CC=golang-dev
https://codereview.appspot.com/12387043

Committer: Rob Pike <r@golang.org>