Most of these files were obtained (as of 2001-12-09) from
http://www.pa.msu.edu/ftp/pub/unix/cd1.3.tar.gz

This software was written originally by G. Edward Johnson at NIST, but it is
no longer maintained by him.  It is public-domain software except for the
small part licensed under the libgd license (see his documentation).

The PLplot developer's contribution is CMakeLists.txt, cddll.h, and some
small visibility modifications to cd.h.  We call the resulting library,
libnistcd to distinguish it from all the other "libcd" libraries out there.
