Add 1.2.40 announcement and release sections

git-svn-id: https://svn.apache.org/repos/asf/tomcat/jk/trunk@1587437 13f79535-47bb-0310-9956-ffa450edef68
Oops. Use correct document link

git-svn-id: https://svn.apache.org/repos/asf/tomcat/jk/trunk@1587439 13f79535-47bb-0310-9956-ffa450edef68