* dsrec.c (load_srec): Add WAITACK parameter, for machines

	* dsrec.c (load_srec): Add WAITACK parameter, for machines
	like EST visionICE that send back an ACK after each S-record.
	* monitor.c (monitor_wait_srec_ack): New function.
	(monitor_load): Pass monitor_wait_srec_ack to load_srec
	if the monitor's MO_SREC_ACK flag is set.
	* monitor.h: Define MO_SREC_ACK flag.
	* remote-est.c (est_cmds): Add MO_SREC_ACK flag.
	* sh3-rom.c (sh3_load): Accomodate change in load_srec prototype.
	* srec.h: Add WAITACK parameter to load_srec prototype.