Allow the ability to set status instead of just status code and status message

When sending a response and setting a status code, it usually returns "OK" in addition to the status code (example: "404 OK"). To remedy this, you have to type `setStatusCode(404).setStatusMessage("Not Found")` (or the equivalent using `HttpResponseStatus`).

In an effort to eliminate a lot of boilerplate code on the framework's users' side, I've added a `setStatus(HttpResponseStatus)` method that will set both the status code and status message.