David Lynch:
	- Change first cache scan approach
	Instead of scanning over every single possible rare, go back to
	scanning just the ones we know of in the zone. Avoid the old problem
	of a notification popping up for mobs like hunter pets the instant
	you enter a zone by making the first scan inside every zone be a
	no-notifications scan.
	
	Big benefit: not being ridiculously expensive in terms of CPU. Cache
	scanning 600 mobs every second? Not cheap.
	
	This does give us the potential edge case of a rare *right next to*
	the zone border not triggering a notification. That seems
	significantly less common than a hunter having tamed a rare, though.
