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.
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