doc: document go1.3.3

LGTM=r
R=r
CC=golang-codereviews
https://golang.org/cl/149280044

doc/devel/release.html

@@ -32,6 +32,11 @@ go1.3.2 (released 2014/09/25) includes bug fixes to cgo and the crypto/tls packa
 See the <a href="//code.google.com/p/go/source/list?name=release-branch.go1.3&r=go1.3.2">change history</a> for details.
 </p>
 
+<p>
+go1.3.3 (released 2014/09/30) includes further bug fixes to cgo, the runtime package, and the nacl port. 
+See the <a href="//code.google.com/p/go/source/list?name=release-branch.go1.3&r=go1.3.3">change history</a> for details.
+</p>
+
 <h2 id="go1.2">go1.2 (released 2013/12/01)</h2>
 
 <p>