Provide a better mechanism for the RewriteValve to inject a re-written request that avoids:
- NPEs appearing in the log every time the Valve re-writes a request.
- unnecessary duplication of post-processing in the adapter

git-svn-id: https://svn.apache.org/repos/asf/tomcat/trunk@1644935 13f79535-47bb-0310-9956-ffa450edef68