【razor】sender：将报文加入到cc的pacer中

sender 是什么

struct __razor_sender
{
   
	int								type;
	int								padding;
	sender_heartbeat_func			heartbeat;
	sender_set_bitrates				set_bitrates;
	sender_add_packet_func			add_packet;
	sender_on_send_func				on_send;
	sender_on_feedback_func			on_feedback;
	sender_update_rtt_func			update_rtt;
	sender_get_pacer_queue_ms_func	get_pacer_queue_ms;</