Performance improvement
Partial fix for https://issues.apache.org/bugzilla/show_bug.cgi?id=55855
Make the adding of the WsFilter lazy so it doesn't get added to web apps that don't need it.

git-svn-id: https://svn.apache.org/repos/asf/tomcat/tc7.0.x/trunk@1551356 13f79535-47bb-0310-9956-ffa450edef68