Bunch of fixes and balance tweaks to the devour system. Notable changes are that xenomorphs can eat people again and that human-types no longer take ridiculous amounts of damage from devour.
changes:
Devour type checks now actually operate on species for human-types and are all-around hopefully more sane.
Replaced an obsolete define with a boolean.
Fixed xenomorphs being unable to swallow human-types.
Rebalanced digestion damage to not kill human-types in one tick.
Digestion now deals fire+brute instead of cloneloss (bite still deals cloneloss as I didn't touch its damage function)
Misc code tweaks.
20150cd113