Fixes issue #555

Fixes #555 
Hostile mobs will now run CanAttack() on the occupant of a mech to determine if they will attack it or not.
Fixes walking shrooms not having full health when spawned due to their health randomization on New()
Adds asteroid mobs and mushrooms and holocarp to the blocked list of gold slime reactions
Removes pointless logging on friendly gold slime reactions now that they can't possibly ever be used for griff