Fixed some bugs (especially hsv<->rgb conversion bugs) and the stone
texture generation is now acceptable. This version uses less efficient
per-column low-frequency strata height computations to get coherent
terrain.

-Peter Mawhorter
Fixed an issue with the near clipping plane.

-Peter Mawhorter
More work on stone types. Basic numbers are all there now.

-Peter Mawhorter
Little tweaks towards baking the current state as a geology demo.
Reduced near clipping plane, made the viewer entity able to walk and
fly, and added a texture for boundary blocks.

-Peter Mawhorter
Finally fixed some bugs with the cleanup code that were causing
segfaults on exit.

-Peter Mawhorter
Worked on getting noise to wrap. Almost there but there's still a bug in
the stone texture generation.

-Peter Mawhorter