Constraint 2D (#147)

* Rename all Constraint by [name]Constraint3D

* Create Refs and Libraries for Constraint2D

* Remove ref to PhysWorld in Constraints ctors

* Update Constraint2d ctor to have RigiBodies first

* Add New static function for all constraints and fix an oopsie

* Add Contraint Library and remove all library useless aliases

* Add ConstraintComponent2D

* remove useless definition of Constraint2D library

* Fix : getting the world of the constraint before having created it

* Make the GetStaticBody function return a ref

* Remove : Useless AddJoint Fonction and Update CreateJoint function

* Update PhysicsSystem3D because GetStaticBody return now a ref

* Oops

* Having done something with the 3D and i was needing 2D

* Add ConstraintComponent as friend of Collision and PhysicsComponent

* Update all the Get[Static/Rigid]Body function so they return a pointer

* fix the bugs caused by the commit before

* update : CreateConstraint lambda for the nullptr case

* remove the useless  use of const pointer

* Update : CreateConstraint function

* Update ChangeLog.md

SDK/include/NDK/Components/PhysicsComponent2D.hpp

@@ -17,6 +17,7 @@ namespace Ndk
 	{
 		friend class CollisionComponent2D;
 		friend class PhysicsSystem2D;
+		friend class ConstraintComponent2D;
 
 		public:
 			PhysicsComponent2D() = default;
@@ -49,7 +50,7 @@ namespace Ndk
 			static ComponentIndex componentIndex;
 
 		private:
-			Nz::RigidBody2D& GetRigidBody();
+			Nz::RigidBody2D* GetRigidBody();
 
 			void OnAttached() override;
 			void OnComponentAttached(BaseComponent& component) override;