AVLTree的实现以及结点的增加删除和查找。-AVLTree the realization of the increase in node delete and search.

纯C实现的AVL树，Demo是MFC的。非递归的遍历，完全支持添加、删除和搜索节点。设计灵活，容易扩展。以下是API struct tagAvlTree; typedef struct tagAvlTree AvlTree; struct tagAvlNode; typedef struct tagAvlNode AvlNode; struct tagAvlNode { AvlNode *left; AvlNode *right; int32_t height;