title: Change TreeNode image on expand-collapse events
body: <p>I have a treeView with many nodes. I want that <strong>some</strong> nodes change their image when node     collapsed/expanded. How can I do it ?</p>
  
  <p>Unfortunately, TreeNode don't have properties like ExpandNodeImage, CollapseNodeImage \</p>
  
  <p>TreeView can change very often, so nodes can be deleted/added.. i can delete child nodes and so on...</p>
  
  <p>Maybe, there is a class like ExpandAndCollapseNode ?</p>