While proper boolean ops between the different more advanced geometry types definitely would require a GEOS module, I'm confident that implementing them for planar 2-dimensional bounding boxes, like the BOX_2D native type would be both useful and comparatively easy.

1. We should make sure to follow the DE-9IM semantics.
2. We should be careful of floating point comparison and precision issues.
3. We might also add a basic point-containement function operating on the POINT_2D type.