Add kkolinko's unit test for https://issues.apache.org/bugzilla/show_bug.cgi?id=55792

git-svn-id: https://svn.apache.org/repos/asf/tomcat/trunk@1543355 13f79535-47bb-0310-9956-ffa450edef68
Fix https://issues.apache.org/bugzilla/show_bug.cgi?id=55792
EL 3.0 introduced the possibility of nested {...} sequences within EL expressions so update the JSP parser to handle them.

git-svn-id: https://svn.apache.org/repos/asf/tomcat/trunk@1543356 13f79535-47bb-0310-9956-ffa450edef68
Add an initial unit test for the WebappClassLoader

git-svn-id: https://svn.apache.org/repos/asf/tomcat/trunk@1543359 13f79535-47bb-0310-9956-ffa450edef68