title: Dynatree: Prevent parent nodes from being selected by default, using select mode 3 (hierarchical)
body: <p>I am using Dynatree with select mode "3", which enables a hierarchical selection mode.</p>
  
  <p>When my tree renders, all nodes that have children render as selected by default. Leaf nodes render unselected by default. If I start manually selecting nodes, the tree behaves as expected.</p>
  
  <p>How can I force <em>all</em> nodes to be unchecked by default?</p>
  
  <p>Notes:</p>
  
  <ul>
  <li>Dynatree 1.2.1 RC3</li>
  <li>Tree starts out empty and is programatically constructed using "addChild()"</li>
  <li>It makes no difference if I explicitly add "selected: false" when building my nodes.</li>
  <li>Have not tried pre-constructing the entire structure.</li>
  </ul>
  
  <p>Thoughts?</p>