* select.cc (struct socketinf): Convert ser_num and w4 to dynamically

	* select.cc (struct socketinf): Convert ser_num and w4 to dynamically
	allocated arrays.  Add max_w4 member to keep track.
	(thread_socket): Make timeout depending on number of sockets to wait
	for.  Loop WFMO over all sockets.
	(start_thread_socket): Handle any number of sockets.  Fix typo.  Don't
	close socket event in out of memory condition.
	(socket_cleanup): Free ser_num and w4.