- this adds support for various STL operations including
* sorting, filling, find min/max element etc.
* for-range iteration
STYLE: use constexpr for VectorSpace rank
- the vector normalise() method modifies the object inplace,
the normalised function returns a copy.
vector vec1(1,2,3);
vec1.normalise();
vs
vector vec1(1,2,3);
vec1 /= mag(vec1) + VSMALL;
For const usage, can use either of these
const vector vec2a(normalised(vector(1,2,3)));
const vector vec2b(vector(1,2,3).normalise());
