Flat walls for Wayfarer Modular Scifi Gaming Tiles

I wanted a slightly different aesthetic for [Dutchmogul's](https://www.thingiverse.com/dutchmogul/about) excellent scifi [terrain tiles](https://www.thingiverse.com/thing:703514).

To make these I basically just overlaid the previous walls with beveled boxes. Not the most artistic thing, perhaps, but they print a good bit faster and use less plastic due to the reduced surface area.

Update: I have also added Dutchmogul's conveyance tiles (ladders and stairs).