Update documentation - PersistenceManager has to be disabled for Tomcat

The Tomcat 5.5 and Tomcat 6 documentation needs to be updated so that the sample files match the new ones we ship. Could you please make this change. You could get in before the developers and make the change. It is simply that:

<Manager className="org.apache.catalina.session.PersistentManager" saveOnRestart="false"/>

needs to be changed to:

<Manager pathname=""/>