title: Automatically change TreeView's selection when adding a node to ViewModel
body: <p>I have a TreeView with a ContextMenu that contains options to add/remove nodes.  When I add a node to the tree, I am currently sending a command to my view model which handles the add request by adding a wrapper for the display tree and a backing data object.  When I do this, I want the newly created wrapper in the display tree to become the selected item of the treeview.  How can I do this?  I don't know how to access the treeview from the viewmodel and suspect that you might not even be supposed to.  Thanks.</p>