Added name fields to Collision Object and Shape.

Added name field to Typed Constraint.
Added accessor for gravity in dynamics world.

src/BulletDynamics/ConstraintSolver/btTypedConstraint.h

@@ -33,6 +33,7 @@ class btTypedConstraint
 {
 	int	m_userConstraintType;
 	int	m_userConstraintId;
+	char*   m_name;
 
 	btTypedConstraintType m_constraintType;
 
@@ -107,6 +108,16 @@ public:
 	{
 		return m_constraintType;
 	}
+
+	char* getName () const
+	{
+		return m_name;
+	}
+
+	void setName (char* name)
+	{
+		m_name = name;
+	}
 };
 
 #endif //TYPED_CONSTRAINT_H