(parse_async): Fixed off-by-one parse error.  Report parse errors
	more verbosely.
(report_progress): New function.  Report progress, but print
	nothing unless we have received a new reply from the server
	since the last time we were called.
(longopts): New constant.
(main): Use getopt_long to parse the arguments.  Enable progress
	report.  Fixed a broken printf format string.