Goal: To support TRILINEAR's using CONTOURPLOT rather than GRAPH so that real
      contour lines will show up on the plot.

1) Need to figure out exactly how to add more than one contour surface
   non-interactively (add some interactively and see how it changes.)

2) Should the same routine be used, or a separate one ?
   (I think they are diferent enough to require different routines. Even from
    the end user point of view, what one specifies is different in a space
    filleng situtation vs an interpolated one.)

    More importantly, no one is going to use the old one with the new one
    around. You cannot afford to maintain all the extra work simply because
    it was there before. 

    Conclusion: Make a separate procedure for this function.

3) 

The bulk of the functionality is already done with the contourplot. All that
has to be done is the function needs to be computed on the X-Y grid equivilant
to the X1, X2, X3 grid. 

The two procedures share only the front-end (information needed from the user.)
Even here, there are certain aspects that are NOT shared; for example, the
"window" for axes labels. 

Issues to consider:

	1) The form of the data table is diferent. (x-Y grid rather than one-d
           table.)

	2) Can pseudo-components be done using the same