title: DataGridCheckBoxColumn immediate binding
body: <p>I'm using the WPF Toolkit Datagrid and have one column which is a DataGridCheckBoxColumn bound to a bool property on my ViewModel.</p>
  
  <p>My problem is that I wan't the property to get it's value updated immediately when the user checks or unchecks the checkbox. </p>
  
  <p>Now you have to navigate away from the cell in order to have the property updated. It's a checkbox. It can't be in the middle of editing like a textbox can.</p>