Explicitly un-create a randomly generated artifact if it gets
rejected (too big to include as a treasure drop with a small corpse)
so that it remains eligible for creation later. And when generating
random contents for a new container, explicitly avoid artifacts
(which were already implicitly avoided).
Closes #599
to pull a monster out of a pit would trigger a divide by 0 crash
avoid "you now detect it where the vampire bat was" when a vampire shifts from
a bat seen with infravision to an unseen fog cloud
+if an artifact gets created as a random treasure drop and then deleted because
+ it is too big to include with a small corpse, explicitly uncreate it
+ instead of just discarding it so that it is eligible for use later
+when creating random contents for a container, explicitly exclude artifacts
+ (already implicitly excluded because randomly generated artifacts are
+ all weapons and containers don't start with any weapons in them)
Fixes to 3.7.0-x Problems that Were Exposed Via git Repository