adds in previously uncaught errors and collects them together by HTTP status code to reduce copy-and-paste coding in previous versions of these files
adding in a couple of additional errors that are thrown from methods invoked from within the model and broker RESTful API classes
Merge pull request #160 from tjmcs/tb/catch-uncaught-api-errors

Fixes #158 (Unhandled Exceptions/Errors in RESTful API)