remove a lot of warnings (more todo in demos and serialization code)

src/BulletDynamics/ConstraintSolver/btContactConstraint.cpp

@@ -155,8 +155,7 @@ void resolveSingleBilateral(btRigidBody& body1, const btVector3& pos1,
 		body1.getCenterOfMassTransform().getBasis().transpose() * body1.getAngularVelocity(),
 		body2.getLinearVelocity(),
 		body2.getCenterOfMassTransform().getBasis().transpose() * body2.getAngularVelocity()); 
-	btScalar a;
-	a=jacDiagABInv;
+
 
 
 	rel_vel = normal.dot(vel);