Update userdata stuff to how new box2d wants it

src/libraries/box2d/b2_body.h

@@ -379,7 +379,7 @@ public:
 	b2BodyUserData& GetUserData();
 
 	/// Set the user data. Use this to store your application specific data.
-	void SetUserData(b2BodyUserData& data);
+	void SetUserData(void* data);
 
 	/// Get the parent world of this body.
 	b2World* GetWorld();
@@ -736,11 +736,6 @@ inline b2BodyUserData& b2Body::GetUserData()
 	return m_userData;
 }
 
-inline void b2Body::SetUserData(b2BodyUserData& userData)
-{
-	m_userData = userData;
-}
-
 inline void b2Body::ApplyForce(const b2Vec2& force, const b2Vec2& point, bool wake)
 {
 	if (m_type != b2_dynamicBody)