Fixed some exception that were not handled if the RawBody was null in the JsonRESTService class.

- Fixed some exception that were not handled if the RawBody was null in the JsonRESTService class.
- Moved all logic in the JsonRestService's main Execute method into the try catch and added a sub try catch inside the outter catch block.  This is so the logger ALWAYS fires.  
- Also added new constructor options.
- Moved the __Response<T>__ object to its own class file __ResponseOfT.cs__