beta versions of time zone stuff

[Olson, Arthur David]

The files
	ftp://elsie.nci.nih.gov/pub/tzcodebeta.tar.gz
and
	ftp://elsie.nci.nih.gov/pub/tzdatabeta.tar.gz
are now available.

1. zic puts "TZif" at the start of each file it outputs.
2. zic looks for lines of the form
	#Updated Zone America/New_York 1997 Nov 19 17:58:00
and
	#Updated Rule NYC 1997 Nov 19 17:58:00
and, when generating output for a zone, stamps the output
with the greatest "Updated" time for the zone or any of the
rules it uses.

Comments heartily solicited!

				--ado