title: belongs_to a specific version
body: <p>I need to store the specific version of a model with an order. I'm planning to use a versioning gem like <a href="https://github.com/airblade/paper_trail" rel="nofollow">paper_trail</a> or <a href="https://github.com/laserlemon/vestal_versions" rel="nofollow">vestal_versions</a>. I'd like the correct version automatically loaded with the order.</p>
  
  <p>Ideally, I'd simply store the object with <code>order.update_attributes(:stuff =&gt; bought_stuff)</code> and the order would remember the version of the stuff so that subsequent loads would make <code>order.reload.stuff</code> still be the object as it was when the order was saved.</p>
  
  <p>Is there a gem that would provide such a functionality? I couldn't find one.</p>
  
  <p>Otherwise, how can I achieve that with ActiveRecord and a versioning gem?</p>