Implement completely the QuadTree. JUnit tests incoming in next commit.

Signed-off-by: Adrien <berthet.a@gmail.com>
Updates POM to add Java 7 rule for building.

Signed-off-by: Adrien <berthet.a@gmail.com>
Add JUnit dependency and JUnit tests for the Tree creation/culling.

Signed-off-by: Adrien <berthet.a@gmail.com>