Offsets and multiple turrets.

The initial video missed some basics which I never thought of. It also didn't contain the more complex methods of working turret spawning. The intention was to bundle them in to more videos, but it became apparent that... they should have been in the first video!

This is mostly how many broken things I've tried to get multiple turrets working. A fraction of what I tried and none of the swearing. Broken assets are included in the downloads if anyone wants to try to get them working.