More license updates for new XSDs

git-svn-id: https://svn.apache.org/repos/asf/tomcat/trunk@1481001 13f79535-47bb-0310-9956-ffa450edef68
Another Java EE 7 XSD license update

git-svn-id: https://svn.apache.org/repos/asf/tomcat/trunk@1481002 13f79535-47bb-0310-9956-ffa450edef68
Add constants for new XSDs
Ensure new XSDs are registered as local schema
Add 3.1 version check to web.xml parsing with the associated unit test

git-svn-id: https://svn.apache.org/repos/asf/tomcat/trunk@1481005 13f79535-47bb-0310-9956-ffa450edef68