Multiple things:

* Rename file name of 3D box model
* Fix invalid passed test count
* Delete old y-axis.txt file
* Update tests for box model
+ Add three new tests

Yes, I know tests are supposed to help guard against regressions, and
indeed they do, but with the parser fully in place, the former file
format required is formally dropped and no longer supported. It was only
that way because I had no yet finished the parser. I have absolutely no
intentions of supporting both, only the formal, correct way.