Add low-health fear state, etc.
Add low-health fear state, etc.

Adjusted "determine_npc_behavior" so that enemies will run, not only
when "intimidated," but also when their health is lower than the current
depth. Also further adjusted the intro narration and GOBLIN/TROLL/OGRE
graphics.

theDrake/pebblequest,theDrake/pebblequest