Expand All Nodes with Async

Explanation of implementation method

• Using 'onAsyncSuccess' / 'onAsyncError' callback and 'reAsyncChildNodes' or 'expandNode' method, you will achieve all functionalities.
• Note: If there are large amount parent nodes, please use delay to avoid excessive asynchronous process.
• Recommendation: please use the debugging tools to view the ajax loading process with network.
• Demonstrate operation
  
  [ Expand All Nodes ]        [ Load all nodes (don't expand) ]
  
  [ Reset zTree ]