added release date

Author: dghgit

docs/releasenotes.html

@@ -24,6 +24,7 @@ <h2>2.0 Release History</h2>
 
 <h3>2.1.1 Version</h3>
 Release: 1.56 <br/>
+Date:&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; 2016, December 23
 <h3>2.1.2 Defects Fixed</h3>
 <ul>
 <li>See section 2.1.4 for Security Defects.</li>