Adds support for Virtual resources to the FileResourceSet (it still needs to be added for the DirResourceSet). This will allow an application to full traverse the resource hierarchy including any non-main resources mounted under a directory structure that does not exist in the main resources.

git-svn-id: https://svn.apache.org/repos/asf/tomcat/trunk@1430353 13f79535-47bb-0310-9956-ffa450edef68
Don't hard code mount path

git-svn-id: https://svn.apache.org/repos/asf/tomcat/trunk@1430368 13f79535-47bb-0310-9956-ffa450edef68