title: PATCH in REST and null
body: <p>We have an article resource with properties:</p>
  
  <ul>
  <li>title</li>
  <li>image</li>
  <li>description</li>
  <li>status: published | draft</li>
  </ul>
  
  <p>if we want only to remove image we make request</p>
  
  <pre><code>{title: null, image: null, description: null, status: null}
  </code></pre>
  
  <p>if we want only to update status we make request</p>
  
  <pre><code>{title: null, image: null, description: null, status: draft}
  </code></pre>
  
  <p>but in this case image also will be removed</p>
  
  <p>How in REST to update only one property?</p>