- Ported from dd_geo/chull to convex_hull_3.
- Changed to new concept naming convention, i.e., WidthTraits_3.
- Changed traits class to new kernel design naming. However, the unchanged
member functions make this traits not compliant with kernel traits.
- Edited Width_3.tex quite a bit. Removed redundant descriptions of type
requirements that are actually described in the WidthTraits_3.