TODO list for the d-dimension kernel:
- Aff_transformations with the whole hierarchy, although need to think
  hard about what the benefits are (cause it's a lot of work)!
  currently, we limit ourselves with the generic representation!
     Homothecy_rep_d.h           Translation_rep_d.h
     Scaling_rep_d.h             Reflexion_rep_d.h
- smaller dimensional flats and simplices
- distances and intersection packages

- homogeneous_solver() in Linear_algebra_d.h
- verify_determinant() in Linear_algebra_d.h
- coplanar_orientation() in predicates_on_points_d.h
- Rename _* to *_ to be std compliant.