fix bug in plane intersection
port Circle primitive
add coloured sunflower-pattern spheres to scene
box geometry and material upon construction
resolve a few warnings
add metal sunflower-pattern spheres to scene
add Sf10GlassMaterial
add Compound

In Luculentus this was called IntersectionCompound.
add functions to create InfinitePrism and ThickPlane
add functions to create Prism and HexagonalPrism
add some prisms to the scene