title: Pass Node env to layout.jade in Express without explicitly defining route
body: <p>So, I get passing parameters to Jade files- piece of pie:</p>
  
  <pre><code>app.use('/myroute', function (req, res) {
    res.render('myview', {somevar: 'Testing!'});
  });
  </code></pre>
  
  <p><strong>However</strong>- I have my layout.jade file that is implicitly read and rendered by Express, with no actual definition of route-view binding, and I'm trying to work out how to pass a variable into that template.</p>
  
  <p>Any ideas? Cheers!</p>
  
  <p>Ps- this is so that I can pass node's development/production variable to some front-end javascript that's being added on every page.</p>