Add parsing for RFC2109 values

git-svn-id: https://svn.apache.org/repos/asf/tomcat/trunk@1621989 13f79535-47bb-0310-9956-ffa450edef68
RFC2109 parser that passes the tests - still several TODOs.

git-svn-id: https://svn.apache.org/repos/asf/tomcat/trunk@1621990 13f79535-47bb-0310-9956-ffa450edef68