Kalman refactor
Refactor of TrackVectorFit.
- Memory related objects have been identified with the namespace Mem.
- Mem:: contains Store, Iterator and ReverseIterator.
- Mem::View:: contains State, SmoothState and NodeParameters.
- Scalar and vectorized math have been moved to respective scalar and vector folders, and have been given a namespace.
- Scalar:: contains scalar predict, update, combined, smoother and math.
- Vector:: contains vectorized predict, update, smoother and math.