Modifies Chloral Hydrate lethality

Chloral used to kill in 15 unit doses on /vg/ and 30 on /tg/.  I'm sick and tired of having accidental murders happen when medbay decides to sedate somebody.  
Chloral now deals no damage in 15 unit doses, 145 damage in 16 unit doses, and kills in 16.4 unit doses.