title: Add a mouse-listener to each row of a grid in Vaadin
body: <p>I have a simple grid in my web application, that is coded like this: </p>
  
  <pre><code>Grid users_list = new Grid();
  users_list.addColumn("username", String.class);
  users_list.addColumn("email", String.class);
  </code></pre>
  
  <p>and I would like to add a mouse-listener (left mouse button) to each entry that will populate the grid. Is this possible in Vaadin?</p>