title: Show translation missing in rails 3 like the rails 2 way
body: <p>Since I'm using rails 3 there are a lot of translation missing records in production environment because of the way translation missing strings are handled in rails 3, for example the output of translation missing is now : </p>
  
  <pre><code>&lt;span class="translation_missing" title="translation missing: fr.admin.orders_logs.update.title"&gt;Title&lt;/span&gt;
  </code></pre>
  
  <p>In our application we see "Title" so we think the translation is ok but infact the translation is missing, if I"m not wrong the displayed text was "translation missing: fr.admin.orders_logs.update.title" in Rails 2.X</p>
  
  <p>How I can activate this again that he shows me the error message instead of putting it just as title in a span?</p>