Changed the health check for crit in life.dm for humans, monkeys, and aliens from < 0 to <= 0.

Fixes that weird issue where people can take 5 laser hits to the face and still run around at 0 health until someone sneezes on them or they stub their toe.
fixed the changelog... could've sworn I pressed reload
removed changelog.html

Well I thought it was game changing :(
Changed all crit checks from static zeros to config.health_threshold_crit
Merge pull request #518 from Malkevin/rasputin

Changed the critical heath check to <=0