Versions

• Added trains and everything related to trains.
• Added a bunch of examples and documentation.
• Added texture 0 colorization.
• Added new geometry commands (rotate, altrot, altpoly, frustum).
• Added symbolic constants for colors, axes, and directions.
• Added "reload" menu command.
• Made two large improvements to the "what's in front" algorithm.
• Fixed it so you can't get stuck inside blocks.

Version 2 - 2013-10-16

• Added clipping.
• Added new geometry commands (scale, glass, polygon, prism, cone).
• Made blocks obstruct user motion.

Version 1 - 2013-09-30

• The original version, with no clipping except backface culling.