@param io the pool the object is in
@param o the name of the object
@param notify_id the notify_id we got on the watchcb2_t callback
@param cookie the watcher handle
@param buf payload to return to notifier (optional)
@param buf_len payload length
@returns 0 on success
Acknolwedge receipt of a notify
@param io the pool the object is in @param o the name of the object @param notify_id the notify_id we got on the watchcb2_t callback @param cookie the watcher handle @param buf payload to return to notifier (optional) @param buf_len payload length @returns 0 on success