Fix https://issues.apache.org/bugzilla/show_bug.cgi?id=57038
Add a WebResource.getCoseBase() method, implement for all WebResource implementations and then use it in the web application class loader to set the correct code base for  resources loaded from JARs and WARs.

git-svn-id: https://svn.apache.org/repos/asf/tomcat/trunk@1628197 13f79535-47bb-0310-9956-ffa450edef68