(** send an "error" response (i.e. 400 <= status < 600), optional body
argument as per send_redirect, default response status is 400 (bad request),
only error status are accepted by this function, other values will
(** send an "error" response (i.e. 400 <= status < 600), optional body
argument as per send_redirect, default response status is 400 (bad request),
only error status are accepted by this function, other values will