MUX_SUBS_RECV ctl flag is added to instruct the mux it should wait for read
events. This flag will be pretty useful to handle abortonclose option.
MUX_STATUS, /* Expects an int as output, sets it to a combinaison of MUX_STATUS flags */
MUX_EXIT_STATUS, /* Expects an int as output, sets the mux exist/error/http status, if known or 0 */
MUX_REVERSE_CONN, /* Notify about an active reverse connection accepted. */
+ MUX_SUBS_RECV, /* Notify the mux it must wait for read events again */
};
/* response for ctl MUX_STATUS */