title: How to serialize/deserialize to `Dictionary<int, string>` from custom XML not using XElement?
body: <p>Having empty <code>Dictionary&lt;int, string&gt;</code> how to fill it with keys and values from XML like </p>
  
  <pre><code>&lt;items&gt;
  &lt;item id='int_goes_here' value='string_goes_here'/&gt;
  &lt;/items&gt;
  </code></pre>
  
  <p>and serialize it back into XML not using XElement?</p>