title: How to keep all items in an ExtJS treepanel visible at all times
body: <p>I have a treepanel listing a complex hierachy of nodes.</p>
  
  <p>If the list of nodes gets too big then the panel scrolls which is desired.</p>
  
  <p>What is not desired is the ability of a user to click the arrow (or dblclick the item) to expand/collapse parent nodes.</p>
  
  <p>What is the simplest way to ensure a treepanel always renders fully expanded and the expand/collapse functionality is removed?</p>