Updated the handling of HTTP status codes in the response

Improved API integrity by blocking the ability to set invalid status codes according to the HTTP spec. This includes any non-numeric codes, or any code that is greater or less than 3 digits in length (100-999 being the accepted range).

From the spec: "The Status-Code element is a 3-digit integer result code of the attempt to understand and satisfy the request."

Spec details here: http://www.w3.org/Protocols/rfc2616/rfc2616-sec6.html#sec6.1