Re-made turret as Archetype
Enemy_Turret DONE

Ok, finally! It's working *exactly* as it should.
Aims in the correct way, fires in the correct way, is disabled the
correct way, added to the Archetype system the right way, removed from
the level the correct way... Unless I'm missing something, I'm pretty
sure the Turret is completed!

I've even removed my test level now, so now I'm just going to be working
levels.

(Sheesh... as ridiculous as this is, this was the most awkward/difficult
thing I've ever coded.)