Update to box2d 2.4.1

src/libraries/box2d/b2_dynamic_tree.h

@@ -23,13 +23,14 @@
 #ifndef B2_DYNAMIC_TREE_H
 #define B2_DYNAMIC_TREE_H
 
+#include "b2_api.h"
 #include "b2_collision.h"
 #include "b2_growable_stack.h"
 
 #define b2_nullNode (-1)
 
 /// A node in the dynamic tree. The client does not interact with this directly.
-struct b2TreeNode
+struct B2_API b2TreeNode
 {
 	bool IsLeaf() const
 	{
@@ -64,7 +65,7 @@ struct b2TreeNode
 /// object to move by small amounts without triggering a tree update.
 ///
 /// Nodes are pooled and relocatable, so we use node indices rather than pointers.
-class b2DynamicTree
+class B2_API b2DynamicTree
 {
 public:
 	/// Constructing the tree initializes the node pool.
@@ -156,9 +157,6 @@ private:
 
 	int32 m_freeList;
 
-	/// This is used to incrementally traverse the tree for re-balancing.
-	uint32 m_path;
-
 	int32 m_insertionCount;
 };