title: Adding "id" properties where there are navigation properties (EF)
body: <p>If I have a navigation property (ie: virtual), for example:<br/>
  <code>public virtual User Author { get; set; }</code></p>
  
  <p>And I want to have also the id of that User, ie:<br/>
  <code>public int AuthorId { get; set; }</code></p>
  
  <p>How can I tell EF that this "AuthorId" must be related to the Author property?</p>
  
  <p>I don't like the idea of this being automatic (EF magically deducing this).<br/>
  Because one could have multiple references to the same table:</p>
  
  <pre><code>public virtual User Author { get; set; }
  public int AuthorId { get; set; }
  public virtual User Receiver { get; set; }
  public int ReceiverId { get; set; }
  </code></pre>