Fixes #2503 - Mechs Vs. Wand of death

Also changed simple_animal/Die() because if you use a mob's death() proc it won't be cancelled out by that mob's life() except simple_animal life() will actually bring the mob back to life if you just flat out use Die() on the mob.

Removed some Variables on the death projectile due to this rework making them fine to just be inherited from the normal magic projectile.

Fixes #2503