Avoid internal NullPointerExceptions if a resource is requested from outside the web application root.

git-svn-id: https://svn.apache.org/repos/asf/tomcat/trunk@1573321 13f79535-47bb-0310-9956-ffa450edef68
DBCP update

git-svn-id: https://svn.apache.org/repos/asf/tomcat/trunk@1573323 13f79535-47bb-0310-9956-ffa450edef68