Addresses issue #218, and details are included there.

Includes four new generation steps:

1. Spiral - carves a walkable, spiral tunnel out of non-walkable space
2. Parallelogram - creates a grid of small, regular parallelograms
3. Backrooms - Creates an irregular area of rooms of varying sizes
4. Composite - Sections the map into a big grid of regions, and then performs a different generation step on each region that is within the map.

Created as a Work in Progress because these steps do not conform to the preferred style of GoRogue's steps, however, we need them in GoRogue's codebase so that we can clean up the integration library for alpha release sooner.