This is a mandelbrot calculator built entirely out of "ordinary" nodes.
(No specials are used.)  The only improvement (and in fact, the only
difference) between this and demo0 is that the task of computing the mandelbort
has been parallelized by hand by manually splitting the image into several
pieces.  Run in the same way as decribed in the README file for demo0.

Note that there is absolutely no change in the C code for this demo; all the
changes are in the HeNCE graph.
