Adds Artillery Shells with a nuclear payload, a super lategame nuke alternative.
Patches Atomic Artillery to have better auto targetting and less overkill.
I refactored the code and adjusted damage, so autotarget works with behemoth worms. After playing my previous 600/600% biters deathworld with 17/17% resources, the issues with targeting annoyed me enough to warrant a patch :)
It makes a surprisingly big difference when you fire thousands of shells.
