Beautiful Egg

This is a smooth, fast, beautiful egg, based loosely on kellyegan's original.

*Improvements:*
- instead of stacking cylinders, this calculates a **complete 3D polyhedron** shape
- **higher polygon density** around both ends of the egg so that it avoids the "pointy tip" phenomenon
- **no rendering artifacts in preview mode**. Because the egg is one solid object, there are no rendering artifacts when viewing the inside of an egg (e.g. when removing portions of an egg, as in a hollow egg).
- **much faster at rendering**. Using a polyhedron (solid shape) is instantaneously rendered in OpenSCAD (both Preview and Render).
- **uniform distribution** of (mostly) square-shaped polygons on the surface creates an appealing surface when printed