Those traits are not really removed since rust cannot handle those multiple operator overloading
very well yet, making them sometimes unuseable on generic code.
Because of the unfortunate changes on type parameters resolution:
- the Dim trait now needs an useless parameter to infer the Self type.
- ApproxEps::epsilon() is broken.
The goal is to make traits less fine-grained for vectors, and reduce the amount of `use`.
- Scalar{Mul, Div} are removed, replaced by Mul<N, V> and Div<N, V>,
- Ring and DivisionRing are removed. Use Num instead.
- VectorSpace, Dot, and Norm are removed, replaced by the new, higher-level traits.
Add four traits:
- Vec: common operations on vectors. Replaces VectorSpace and Dot.
- AlgebraicVec: Vec + the old Norm trait.
- VecExt: Vec + every other traits vectors implement.
- AlgebraicVecExt: AlgebraicVec + VecExt.
