Since we don't need client implementations any longer, given the maturity level of
qpid jms, these classes can go, as a result a lot of the interfaces can be removed.
As part of this I am removing proton-plug, and reorganizing the packages in a way I think it
makes more sense and easier to other developers to understand and maintain it.
https://issues.apache.org/jira/browse/ARTEMIS-751
Javax.json is a newer JSR, but has an ASF compliant version, is pretty close to the original JSON.org API and will support a standard annotation based JSON-B solution at some point soon.
Updated integration tests and removed JSON.org from license.