Using a separate ABM for this. We may want the burn-up effect with
containers later, but it may have to be handled differently in
those cases as the container itself may have flammability
characteristics to take into account.
This SHOULD also resolve the problem with transient states of the
stack node (i.e. wherein it was temporarily empty) burning up,
which caused some things to burn up when they shouldn't.
Particularly egregious was the destruction of hot lode prills when
they dropped into forgefire.
Appears to work with existing functionality.
Next step will be to rework pummel to use a "recipe" system and
reuse most of the useful parts of the crafting system.
"Loose" versions of materials will only allow a certain maximum
angle of repose, and will shuffle around sideways and fall if
that angle is exceeded. Softer materials like sand, leaves, loose
items, will all have shallow angles, while sturdier stuff like
dirt, gravel, etc. may allow steeper ones.
