Check witness_dead in more functions to avoid panic'ing when assertions fail due to witness exhausting its internal resources and shutting down.
Check witness_dead in more functions to avoid panic'ing when assertions
fail due to witness exhausting its internal resources and shutting down.

Reported by:	Szilveszter Adam <sziszi@petra.hos.u-szeged.hu>
Tested by:	David Wolfskill <david@catwhisker.org>

jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase