First glueing of the ball

Still not very clean (circular inclusion)
Added GitIngnore File
Collision with walls and paddle added

Fonctional collision but still relying on a pattern issue (Ball.h
includes Paddle.h ...)
Yet part of code is there.
Small changes in collision

Improved the collision with the walls and paddle
Small cleaning of Ball
Ball class cleaning
Useless changes
Construction of CollisionDetectorClass
Collision Detection functions additions
Useless changes
Cleaning of Ball class for proper patterns
First changes in CollisionDetector
Creation of two classes and remakes
Trying to do something efficient...
Some clarifications

- deleted previous detection
- created AABB struct to simplify and abstract the problem
- begin some collision detection (it works)
COLLISION DETECTION !

We can now detect the collisions. We still do not treat them and resolve
them yet.
Merge pull request #1 from HugoViala/Collision_FirstTry

Collision Detection