Add PhysicEngine::generateContacts(...), Contact and Vector2::normalize()
Implement all the contact generation beetween two spheres
Add the Collision Engine:
Overload operators for Vector2
Remove -Og from the Makefiles
Add precision to the Collision Engine
Add the removal of outside-screener balls and add the restitution coefficient
Make the paused balls solid:
Add bypassing paused objects option to EntityManager's get*Component*() and getObjectTable()
The physic engine now considered objects with paused Velocity as a still immovable object
Remove the mass in the computation of gravity and put it in the formula of the initial velocity
Add the possilibity to change from red to green for the balls
Add a little shape to vizualize the deltaMouse_