Engine updates to enable Web Services improvements

I've implemented the agreed upon REST and SOAP services. I've also added a WSDL generating plugin for the SOAP services, so the end users wouldn't be limited only to CXF clients. 

Also, I first started building my own POJO mappers, in a way similar to your JsonFactory, but that got too complex at some point (too many mapper classes had to be implemented) so I dropped that and used Dozer instead, which is a much more flexible and elegant solution in my opinion. Aside from that, I decided it would bring too much code duplication to use separate POJO classes for REST and SOAP services so I used the same ones and moved them to common.

The implemented web services were tested with REST Client and SoapUI.