title: rails3 cancan load_resource for custom actions
body: <p>I am using cancan 1.6.8 in my application.</p>
  
  <p>I have to create a Cart in my custom method. So I have added custom actions in my routes.rb. Example:</p>
  
  <pre><code>resources :carts
     collection do
       get "new_cart"
       post "create_cart"
     end
  end
  </code></pre>
  
  <p>How to initialize new object(<code>@cart = Cart.new</code>) using <strong>load_resource</strong> for my custom methods(new_cart, create_cart) ?</p>