One of the last parts of the refactoring (hopefully), made most members of btCollisionObject protected.

Also did some work on improving the constraint solver.

src/BulletDynamics/Dynamics/btDynamicsWorld.h

@@ -19,6 +19,8 @@ subject to the following restrictions:
 #include "BulletCollision/CollisionDispatch/btCollisionWorld.h"
 class btTypedConstraint;
 class btRaycastVehicle;
+class btConstraintSolver;
+
 
 ///btDynamicsWorld is the baseclass for several dynamics implementation, basic, discrete, parallel, and continuous
 class btDynamicsWorld : public btCollisionWorld
@@ -65,6 +67,8 @@ class btDynamicsWorld : public btCollisionWorld
 
 		virtual void	removeRigidBody(btRigidBody* body) = 0;
 
+		virtual void	setConstraintSolver(btConstraintSolver* solver) = 0;
+
 };
 
 #endif //BT_DYNAMICS_WORLD_H