title: Require returns an empty object
body: <p>I have a folder, that has index.js and a couple of models (classes)
  index.js</p>
  
  <pre><code>module.exports = {
     Book : require('./book'),
     Author : require('./author')
  }
  </code></pre>
  
  <p>book.js</p>
  
  <pre><code>var Author = require('./author')
  var Book = models.ActiveRecord.extend({
      schema : {
          belongsTo : {
              author : Author
          }
      }
  })
  module.exports = Book
  </code></pre>
  
  <p>author.js</p>
  
  <pre><code>var Book = require('./book')
  var Author = models.ActiveRecord.extend({
      schema : {
          hasMany : {
              author : Book
          }
      }
  })
  
  module.exports = Author
  </code></pre>
  
  <p>The problem is that Author class does not seem to find the Book! It's just an empty Object.
  However, if I switch the exports in index.js, putting Book after Author - it works, but then the other model stops working.</p>
  
  <p>I don't want to do any hacks to make it work.</p>