Numerical code directory structure



Previously I had proposed on putting the numerical code in
src/slatec.  I've revised my thinking on this slightly

My proposal for the directory structure is:

src/
  numerical/
    f2cl-package.lisp
    f2cl-macros.lisp
    slatec.lisp
    slatec/
      <Lisp files of converted routines>
      fortran/
        <Fortran files used for conversion>

If we should add routines from other packages, we can just add a new
directory as needed.

Also, to keep symbol clutter down a bit, I'd like to add the SLATEC
stuff in its own package "SLATEC" and just export the
symbols/functions needed by maxima.  (We are currently using 63 names
from SLATEC.)  This is what the slatec.lisp file is for.

This is what I have in my working sources, and everything is basically
working.  Still needs some more work.  However, in(x,n) is broken.  It
always returns in(x,n).  Maxima 5.6 doesn't have this problem.

Ray