Fix https://issues.apache.org/bugzilla/show_bug.cgi?id=56882
Fix regression in processing of includes and forwards when Context have been reloaded.
Tomcat was responding with HTTP Status 503.

This includes test cases.
TestMapper:
Amend context mapper tests
- Check wrapper names
- Test mapper map() method used by include and forward mapping
- Add test for Context reload (BZ 56882)

TestMapperWebapps:
- Add test for Context reload (BZ 56882)

git-svn-id: https://svn.apache.org/repos/asf/tomcat/trunk@1620326 13f79535-47bb-0310-9956-ffa450edef68