tzcode1997c.tar.gz and tzdata1997d.tar.gz

[Arthur David Olson]

The files
	ftp://elsie.nci.nih.gov/pub/tzcode1997c.tar.gz
and
	ftp://elsie.nci.nih.gov/pub/tzdata1997d.tar.gz
are now available. Included are changes to "zic.c" to correct performance of
the "-s" option, and a new file "usno1997".

				--ado