* Added Icosahedron mesh, a multilevel 3D TriangleMesh, that evolves to an Icosphere. Level 8 gives around one million nodes.
* Include the hability to add a density function, to generate a contour plot of this function plotted over the icosphere.
* Added Palette, a utility class to generate tiny images with all the colors required for textures.
* Added several utility methods to Point3D.
* Added a test to generate and show an icoshere. 
* Added animation to change dynamically the density function, diameter or number of colors without rebuilding the icosphere