[1.12.13] Release readiness

- Updated README with information on this release.
- Updated VERSION constant.

README.md

@@ -7,12 +7,16 @@ Master: [![Build Status](https://api.travis-ci.org/zendframework/zf1.png?branch=
 RELEASE INFORMATION
 ===================
 
-Zend Framework 1.12.13dev Release.
-Released on MMM DD, YYYY.
+Zend Framework 1.12.13 Release.
+Released on May 20, 2015.
 
 IMPORTANT FIXES FOR 1.12.13
 ---------------------------
 
+- [#567](https://github.com/zendframework/zf1/pull/567) fixes an issue
+  introduced in 1.12.12 whereby header value assertions were too strict,
+  and did not allow integer or float values.
+
 See http://framework.zend.com/changelog for full details.
 
 NEW FEATURES

library/Zend/Version.php

@@ -32,7 +32,7 @@ final class Zend_Version
     /**
      * Zend Framework version identification - see compareVersion()
      */
-    const VERSION = '1.12.13dev';
+    const VERSION = '1.12.13';
 
     /**
      * The latest stable version Zend Framework available