Hardkernel ODROID-XU4Q passively cooled case

Same base as the "Odroid XU4 case" by apedroid, but the top has a 41mm x 41mm hole for the ODROID-XU4Q's passive heatsink. The heatsink is nominally 40mm x 40mm, so this provides a small gap.

How it was made: apedroid's STL was imported in Blender and I did a boolean difference with a 41mm cube. I then fixed mesh with the [Blender 3D Printing Toolbox](https://wiki.blender.org/index.php/Extensions:2.6/Py/Scripts/Modeling/PrintToolbox) to make sure it was manifold.

Print each part with flat