+ need to reset rigid body using 'setCenterOfMassTransform' to reset world inertia tensor

+ fixes in compound algorithm -> recompute contact points
+ add debug drawing to some demos.
+ revert btJacobianEntry change
+ replace dCROSSMAT by btVector3::getSkewSymmetricMatrix

src/BulletDynamics/ConstraintSolver/btSliderConstraint.cpp

@@ -119,6 +119,8 @@ void btSliderConstraint::buildJacobianInt(btRigidBody& rbA, btRigidBody& rbB, co
     {
 		normalWorld = m_calculatedTransformA.getBasis().getColumn(i);
 		new (&m_jacLin[i]) btJacobianEntry(
+			rbA.getCenterOfMassTransform().getBasis().transpose(),
+			rbB.getCenterOfMassTransform().getBasis().transpose(),
 			m_relPosA,
 			m_relPosB,
 			normalWorld,