title: Change "back" NavigationItem text in Monotouch?
body: <p>Is it possible to change the "Back" button text in a <code>NavigationItem</code>? At present, the caption of the back button assumes the title of the previous layer in the navigation stack, which is expected.</p>
  
  <p>However, the <code>NavigationItem</code>'s <code>LeftBarButtonItem</code> can be changed using code such as this:</p>
  
  <pre><code>UIBarButtonItem backButton = new UIBarButtonItem("Back", UIBarButtonItemStyle.Plain, null);
  myNewView.NavigationItem.SetLeftBarButtonItem(backButton, true);
  </code></pre>
  
  <p>This works and the back button is displayed as expected, but the button is a square and does not navigate back to the previous layer as expected. I'm guessing that the correct event needs to be assigned to it, but I have no idea what it should be. </p>
  
  <p>How would one go about ensuring that the new <code>UIBarButtonItem</code> has the correct event and arrow shape?</p>
  
  <p><b>Note</b>: I have also tried re-using the `LeftBarButtonItem' as suggested in this <a href="https://stackoverflow.com/questions/2846539/adding-back-button-to-navigation-bar">SO question</a>, but I still don't know how to customize the button caption. I am probably just missing the obvious.</p>
  
  <p>Thanks!</p>