Clean up memory if there are turnstate errors.
Make venom into a temporary object.

This makes a few incidental cleanups to the mkobj code. Additionally, venom is
no longer wishable.
Use temporary objects for scroll effects & naming.

I think this clears up mostly everything into a neat temporary object package.
Clean up lava code.

This fixes SC342-3, apparently.
Always print messages for items burning in lava.

The previous behaviour didn't make sense because this meant that, at least from
a visible perspective, the timing of object destruction is inconsistent. If you
have life saving, they appear to burn up beforehand; if you do not, they appear
to burn of afterward (this is observable with bones files, which require a
wizard to make because lava is naturally only on special levels, but it could
theoretically happen). Also cases where wizmode cannot observe a behaviour are
dumb.
Merge remote-tracking branch 'coppro/savebreak' into savebreak

Conflicts:
	libnethack/src/potion.c
	libnethack/src/trap.c
Fix capitalization in #overview

Patch by GreyKnight.

Fixes #273.