Start of a new framework for UTF-8 testing. I have discovered that the correct replacement behaviour (that we want to use for URIs) has many, many edge cases. This class should make it easier to construct additional tests.

git-svn-id: https://svn.apache.org/repos/asf/tomcat/trunk@1452152 13f79535-47bb-0310-9956-ffa450edef68