title: Automapper nested relationship "back" mapping
body: <p>Let's say I have a nested DTO, like this (in reality it is a lot more complex):</p>
  
  <pre><code>public class OrderDTO
  {
      public int Id { get; set; }
      public List&lt;ItemDTO&gt; Item { get; set; }
  }
  
  public class ItemDTO
  {
      public int Id { get; set; }
  }
  </code></pre>
  
  <p>that maps to:</p>
  
  <pre><code>public class Order
  {
      public int Id { get; set; }
      public List&lt;Item&gt; Item { get; set; }
  }
  
  public class Item
  {
      public int Id { get; set; }
      public Order Order { get; set; }
  }
  </code></pre>
  
  <p>When mapping from the OrderDTO down to Order, I would like that the Order property from Item references its order, as to make something like <code>var order = item.Order;</code> possible.</p>
  
  <p>Is there any way I can do that when mapping? Also, is it possible to configure that for all my nested mappings?</p>