Rotation is now fixed, non-moving, and deterministic. This fits
in better with the rest of the visuals in the game being
stationary when in steady-state, i.e. only things actually changing
are actually moving.
Instead of rotation speed indicating a full stack, rotation angle
now does; non-full stacks will always be off significantly from
orthogonal, while full ones will be perfectly square.
- Make node match operate on only one of node or stack, depending
on whether node defers to stack via is_stack_only. This should
hopefully prevent future pummel recipe issues.
- Add new core stack API. Needs to be deployed in a lot of places.
- Start work on system for allowing flammable containers; they
eject their potentially non-flammable contents.
