PicoGK v2.1

This release adds a number of new features for dealing with coordinates, including non-Cartesian ones.

Release Notes

NEW: Added Polar 2D coordinate type
NEW: Added Cylindrical 3D coordinate type
NEW: Added Spherical 3D coordinate type
NEW: Added Viewer.AddCross and Viewer.AddArrow functions
NEW: float.bAlmostZero and Vector3.bAlmostZero extension functions.
NEW: Added float.bAlmostLessOrEqual and float.bAlmostMoreOrEqual extension functions.
NEW: Vector3/Vector2 extension functions vecNormalized and vecSafeNormalized.
NEW: Vector3 extension functions to convert from local to world coordinates and back. You can now write vec.vecPtWorld(from) etc.
NEW: Added Rad.TwoPi constant to avoid having to constantly write 2*float.Pi for angles in radians.
FIX: Renamed Frame3d.vecFromWorld to Frame3d.vecPtFromWorld for consistency