Adds onDecay event to Chemical Turtles

bit buggy right now - doesn't fire when you have the turtle inventory
open
Advanced Turtle AI

Mwahahahahahahaha
That is all
Reworked Radiation

Radiation decay now fires a proper forge event
onDecay now works perfectly
teensie bit of refactoring because instace bugs me
Merge pull request #408 from hilburn/1.7-update

Turtle Updates