add support for picking, using point 2 point constraint

allow to remove constraints by unique id
added tiny wavefront loader, plan to use this instead of existing slow wavefront loader

src/Bullet3OpenCL/RigidBody/b3GpuRigidBodyPipeline.h

@@ -57,6 +57,7 @@ public:
 	
 	int createPoint2PointConstraint(int bodyA, int bodyB, const float* pivotInA, const float* pivotInB);
 	int createFixedConstraint(int bodyA, int bodyB, const float* pivotInA, const float* pivotInB, const float* frameOrnA, const float* frameOrnB);
+	void removeConstraintByUid(int uid);
 
 	void	addConstraint(class b3TypedConstraint* constraint);
 	void	removeConstraint(b3TypedConstraint* constraint);