3 new constraints added : btGeneric6DofSpringConstraint, btUniversalConstraint, btHinge2Constraint

Motors for btConeTwistConstraint added (for obsolete solver only)
appConstraintDemo changed to test new constraints
Several coding-style fixes

src/BulletDynamics/Dynamics/btDiscreteDynamicsWorld.cpp

@@ -1368,7 +1368,7 @@ void btDiscreteDynamicsWorld::debugDrawConstraint(btTypedConstraint* constraint)
 			break;
 	}
 	return;
-} // btDiscreteDynamicsWorld::debugDrawConstraint()
+}