strconv: update to unicode 6.2.0 Fixes build, too.
strconv: update to unicode 6.2.0
Fixes build, too.

R=golang-dev, rsc
CC=golang-dev
http://codereview.appspot.com/6775088
abustany/go,abustany/go,abustany/go,abustany/go,abustany/go,abustany/go,abustany/go