Fix withdrawal deaths

A few of the addictions were causing deaths with their withdrawal symptoms due to reducing the player's stim value to low. Since people don't actually die of these withdrawals in real life, this adds checks to prevent the stim from dropping so low it is deadly. (IRL just about the only addiction withdrawals that can kill you are opiates and alcohol, the rest make you feel crappy, but won't actually kill you on their own).

Also updated the style of this function, new checks are on lines 16, 28, 107, and 161.