Mouse and spiderbot ventcrawl verb is out of date

Created by: unid15

Aliens, monkeys and other ventcrawlers use the handle_ventcrawl() proc, while mice and spiderbots don't

This results in harder ventcrawling for mice and spiderbots as the list of vents isn't sorted, and they always crawl to the most bottom-left vent in the area instead of being able to choose a particular vent. This makes cargo warehouse and possibly some other areas impenetrable to mice & spiderbots.