Fix https://issues.apache.org/bugzilla/show_bug.cgi?id=55345
Handle ServletContext.getRealPath("") in the same way for tc8 as for earlier versions.

git-svn-id: https://svn.apache.org/repos/asf/tomcat/trunk@1509839 13f79535-47bb-0310-9956-ffa450edef68
Use the same Map implementation for user properties to prevent implementation conflicts

git-svn-id: https://svn.apache.org/repos/asf/tomcat/trunk@1509847 13f79535-47bb-0310-9956-ffa450edef68