add a JsonPatchApplier and test.

This creates and applies Json Patch documents to java entities via Jackson and the json-patch library by Francis Galiegue, with the expectation that it's being used in a JAX-RS environment.
simplify test - remove jpa/jta stuff
(original design had JsonPatchApplier running an entityManager.merge() operation, which required all this)
finish RESTService integration with new JsonPatchApplier