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

ChangeLog.md

@@ -51,6 +51,7 @@ Nazara Engine:
 - Calling PlacementDestroy on a null pointer is now a no-op (was triggering an undefined behavior)
 - Fix OBJParser relative offsets handling
 - Add JPEG image saver
+- Update Constraint2Ds classes (Add : Ref, Library, ConstRef, New function and Update : ctors)
 
 Nazara Development Kit:
 - Added ImageWidget (#139)
@@ -81,6 +82,7 @@ Nazara Development Kit:
 - It is now possible to disable synchronization between a PhysicsComponent3D and the NodeComponent
 - Fix PhysicsComponent3D copy which was not copying physics state (such as mass, mass center, damping values, gravity factor and auto-sleep mode)
 - Fix TextAreaWidget::Clear crash
+- Add ConstraintComponent2D class
 
 # 0.4: