Updates README with some notes on design conventions, etc
Changes all the protected methods for Dto class to public so that we can use them generically if needed.
Further revises Dto base class (forgot it was abstract), reorganizes it, just exposes to/from json publicly so those don't require additional methods in every implementation, and adds a new GenericDto to provide us with the generic implementation that we actally need.
Refactors RestResponse to become the generic HttpResponse that it really is, and introduces JsonResponse which is more REST-specific as an extension of it