Added default notFound and serverError responses- should be further tested before merging back in to master.
Went ahead and added the other documented default api response modules as implicit built-ins in core
Remove {status:404} as the default 404 handler when no 'res.notFound()' is present in favor of the Express default convention- just sendingthe words 'Not Found' in the http response body (this case is only relevant/will only occur if/when the responses hook is disabled- in other words, very uncommon)
Added comments/clarifications in default handler code (404/500).
Adjusts test that relied upon the happenstance of the usage: res.send(statusCode, body) without recognizing that the order of those arguments is sometimes flipped.
Merge branch 'master' into bundleresponses