NPC AI

Npc Ai is coded in python in a read-only fashoin. The following algorithm should
replace the stack do_cmd method.

order = None
try:
    order = self.next_order()	# next_order promises not to modify anything
except *:
    # should assume the worst and do some cleanup here and report error
    pass
if order:
    order_list = utils.parse(order)
    self.do_order(order_list)


python -> alang -> python	#the intermediate step isolates errors and
				#requires npcs to be restricted to the same
				#command set as players