title: DataGrid bind command to row select
body: <p>I want to execute a command when the user selects a row in a DataGrid.</p>
  
  <p>I see it is possible to  wrap cell contents in buttons (although I don't want the button style) - but I don't want to do it at the cell-level.</p>
  
  <p>I also see it's possible to use behaviours to link a command to an event. But preferably I should not have to resort to behaviors for such a common task.</p>
  
  <p>Is it possible to do this via plain old command databinding?</p>
  
  <p>So: 1) user clicks DataGrid row 2) command on view model is fired.</p>