OZP-73 Added a UnitOfWorKFilter to the REST project. This filter will begin and then close a unit of work per request. This introduces an explicit dependency on the Persistence API where before this dependency may have been implicit. Could not register this filter as a Servlet filter because the CXF servlet takes precedence and the servlet filter would not be executed during REST requests. Pax Web does not allow us change the order of Servlet Filters so we needed to use a CXF Filter which
is unfortunately part of CXF but not the JAX-RS spec.