Emacs go-mode: fix Emacs freeze-up when copy/pasting from string or comment.
Emacs go-mode: fix Emacs freeze-up when copy/pasting from string or comment.

Fixes issue 3509.
Fixes issue 2767.

R=golang-dev, sameer
CC=golang-dev
http://codereview.appspot.com/6139066

Committer: Sameer Ajmani <da4a4efb907a17fabb3e092841511e7f24e226cf@golang.org>
abustany/go,abustany/go,abustany/go,abustany/go,abustany/go,abustany/go,abustany/go