crypto/rand: Example for Read.
crypto/rand: Example for Read.

R=adg, remyoudompheng, rsc, r
CC=golang-dev
http://codereview.appspot.com/6457085

Committer: Andrew Gerrand <395a7d33bec8475c9b83b7d440f141bcbd994aa5@golang.org>
abustany/go,abustany/go,abustany/go,abustany/go,abustany/go,abustany/go,abustany/go