Prevent unique monsters waking up prematurely

Prevent unique monsters waking up prematurely

Reported by Stefan:
> I just did the valkyrie quest. When I arrived on quest goal, I took only
> a few steps away from the upstairs and Lord Surtur jumped me. One of the
> monsters in his lair had stepped on one of the guaranteed squeaky boards

Squeaky boards (and other noisy things) woke up monsters that were
meditating. Unfortunately this also woke up such meditating monsters
as the Wiz, or the quest nemesis.

Prevent unique monsters with waiting strategy being woken up by the noise.