Restore the ServletContextListener for the Drawboard example to be able to shutdown the Room (dispose of Graphics2D) when the Context is destroyed.

git-svn-id: https://svn.apache.org/repos/asf/tomcat/trunk@1532765 13f79535-47bb-0310-9956-ffa450edef68
Tab policy

git-svn-id: https://svn.apache.org/repos/asf/tomcat/trunk@1532766 13f79535-47bb-0310-9956-ffa450edef68