Fix https://issues.apache.org/bugzilla/show_bug.cgi?id=55046

      Add a Filter that implements CORS (http://www.w3.org/TR/cors/)
Based on a patch by Mohit Soni.

git-svn-id: https://svn.apache.org/repos/asf/tomcat/trunk@1489385 13f79535-47bb-0310-9956-ffa450edef68