P0-B4: Part 1191: Debugging, Improvements

I have made some improvements to the random generation algorithm.

I can now generate forests and ground cover around all settlements, with a clearing in the center for the settlement itself.

Previously, I could only prevent ground cover from appearing on the entire chunk, which led to an obvious blocky appearance to the forests, etc.

This was somewhat complex, but seems to work well.

I also made some other minor changes to the random generation system.

The next step is to try to find a way to connect random settlements together by roads, with collison (preventing trees, etc, from appearing in the way) and with persistence.

I also need to work on the artwork for the next random generation module.