integer and double vectors can be added or subtracted, tests.
Implemented shiftPosition() to move to a relative location.
Corrected encapsulation of Positioned, Scaled and Colored classes.
Oriented class.
Explicited constructors.
Physics now do not crash at the expense of mass (density always allowed).
Physics now correctly ticks.
Physics kinematics added and fixed a memory leak about ball mass.
More physics options.
Physics event shall be sent but no collision yet.
Collisions now occur, ball physics needs a diameter instead of a radius.
Implemented an orientation algorithm with physics.
Mesh physics interface now inspired from the mesh display one.
Mesh physics implementation completed.
Improved orientation and scale of mesh physics.
New physics restitution parameter.