[gfsd]wrong link on Calc page

[roland . kaufmann]

                                Hello,
the following links on the GNU Calc page
  http://www.gnu.org/gnulist/production/calc.html
are wrong (they point to information about a different program with
the same name):
  http://www.isthe.com/chongo/tech/comp/calc/index.html
  http://www.isthe.com/chongo/src/calc/
  http://www.debian.org/Packages/unstable/math/apcalc.html
These describe Calc--C-style arbitrary precision calculator by Landon
Curt Noll (who AFAIK did not have anything to do with GNU Calc, the
Emacs calculator by Dave Gillespie).  I suspect that the version
number is incorrect too, I have 
  v2.02f by Dave Gillespie
which older than March 1997 on my Debian GNU/Linux system.

Hope this helps,
Roland