Added Comparable to the CubicPopulators in order to make an orderable generation && caching Heightmaps in order to use on another generators

[z3nth10n]

Added Comparable to the ICubicPopulators; changed HashSet --> TreeSet on EarthTerrainProcessor; added line to .gitignore; created method to check if the current cube is a road cube

I need it to check for the cubes that generates roads on my Lost Cities port:

https://github.com/uta-org/LostCities-Patched

Also, I realized that the .gitignore file needed to exclude a "logs" folder that it was created when a new MC instance is created.

[orangeadam3]

Uhhh.... mabye. I think a list would accomplish just as much as a comparable set would, and caching might slow evreything down, the ( It would be nice not to have to estimate surfaces, but not evrey saved chunk is necessarily populated )

[z3nth10n]

Catching could be removed later, just as an idea, but it's required for any other mod that requires the heightmaps. (Is slower guessing the height or getting the surface blocks for every block)