Porting obstacles and collision detection

[PFGimenez]

Require issue #1

There are a few classes to port for the obstacles and collision detection. The files to port are : CircularObstacle.java, Obstacle.java, CompoundObstacle.java and RectangularObstacle.java.

Java sources : https://github.com/PFGimenez/The-Kraken-Pathfinding/tree/kraken-cpp/core/src/main/java/pfg/kraken/obstacles

English is the mandatory langage, please translate any french words.
Remember to comply with ROS style guide

[PFGimenez]

Obstacle is for me

[PFGimenez]

And CircularObstacle

[kay0u]

RectangularObstacle (https://github.com/PFGimenez/Kraken-cpp/tree/rectangularObstacle)
From (https://github.com/PFGimenez/Kraken-cpp/tree/obstacles)

[PFGimenez]

#18