v0.7.0 Add pga3dPhysics module

Has a lot of breaking changes.

Add module pga3dPhysics:

1. Different representations for Inertia - as diagonal, moved diagonal, as summable tensor and as cached for faster computations.
2. Helpful classes for physics - Pga3dForque, Pga3dBodyState, Pga3dPhysicsBody
3. Different solvers. The most interesting are explicit Runge-Kutta method of 4th order and implicit method of Gauss-Legendre (4th order too).

Add module for matrices, implement matrix diagonalization. Used for inertia tensor diagonalization.

Profile code a bit, add FastRange class, which is much more efficient for iterating between small values, for examle from 0 until 4 in matrix code.

Add macro for packing case classes with double fields into double array and for unpacking them back.