Consider Moving to Newer Miniball

[giuliabaldini]

We are currently using this version of miniball, but here it is mentioned that

For small dimensions like 2D or 3D, Bernd Gärtner's code, which is based on Welzl's algorithm, may be faster.

So maybe it makes sense to change to the newer miniball version. If we do, we also need to change the license (GPLV3 -> Apache).