add hierarchical node

include/ifaces/ILink.h

@@ -13,4 +13,5 @@ public:
 	virtual const std::vector<std::shared_ptr<TElem>>& getChildren() const = 0;
 	virtual void addChild(const std::shared_ptr<TElem>& child) = 0;
 	virtual void removeChild(const std::shared_ptr<TElem>& child) = 0;
+	virtual void replaceChild(const std::shared_ptr<TElem>& oldChild, const std::shared_ptr<TElem>& newChild) = 0;
 };

include/ifaces/INode.h

@@ -10,4 +10,5 @@ class INode : public virtual ILinkMixin {
 public:
 	~INode() = default;
 	virtual const std::string& name() const = 0;
+	virtual const std::string& kind() const = 0;
 };