Error marshals the JSON representation of err to w.

JSON is shorthand for JSONStatus(w, v, http.StatusOK).

JSONStatus marshals v into w.

ProtoJSON is shorthand for ProtoJSONStatus(w, m, http.StatusOK).

ProtoJSONStatus writes the given value into the http.ResponseWriter and the given status is written as the status code of the response.

RenderableError is the set of errors that implement the basic Render method.

StatusCodedError is the set of errors that implement the basic StatusCode function.