Changed the minimize3() and maximize3() methods of Vector4 to include the M suffix to make it clearer that they are mutation methods.
Re-organized some calculations in DielectricMaterial.
Added a new dielectric material that is optimized for path tracing, DieletricPTMaterial.
Moved Map base classes from raytrace.map to math.map
Added several new distance functions to Vector4.
Fixed a spelling mistake.
Added a nearest nth selection function object for using with Worley noise.
Added a euclidean distance function object.
Added a manhattan distance function object.
Added a tchebyshev distance function object.
Added a simplex noise implementation based on Ken Perlin's 2002 paper.
Added a Worley noise implementation based on an online tutorial.  See source code for full credits and licensing information.
Added a test blend to TestScene6.