more effectively use the polymorphism of PixelGridGenerator to allow the client program to specify the algorithm used by ImagePanel
add CogPar mathematical expression parser
Moved everything out of the default package into the com.laserscorpion.ImageGeneratorLibrary package.

Created SurfaceFlattener subclass of PixelGridGenerator, which interprets arbitrary 2-dimensional surfaces of z(x,y) coordinates.
It lacks absolute value, unfortunately. It can be made much more efficient fairly easily, but it works.