[DGD] Kotaka v0.28

[Raymond Jennings]

Mostly a maintenance release.

The geometry subsystem has been gutted though, while it shows promise I
have a lot more groundwork to do to make it efficient, plus there's the
issue of backward compatibility with the classic containment hierarchy of
environment and inventory that is already in place.

As a prototype though it held its own and proved that a full coordinate
system is feasible.