minor fixes, only btBvhTriangleMeshShape should provide getShapeType(), add get methods for motor limits in btHingeConstraint.

src/BulletDynamics/ConstraintSolver/btHingeConstraint.h

@@ -109,6 +109,17 @@ public:
 
 	}
 
+	btScalar	getLowerLimit() const
+	{
+		return m_lowerLimit;
+	}
+
+	btScalar	getUpperLimit() const
+	{
+		return m_upperLimit;
+	}
+
+
 	btScalar getHingeAngle();