title: HtmlAgilityPack produces missing closing tags in OuterHtml
body: <p>I am using HtmlAgilityPack to parse and manipulate html text. However it seems the DocumentNode.OuterHtml gives missing closing tags.</p>
  
  <p><em>To isolate the issue now I am doing nothing else just parse and get the OuterHtml (no manipulation):</em></p>
  
  <pre><code>var document = new HtmlDocument();
  document.LoadHtml(myHtml);
  result = document.DocumentNode.OuterHtml;
  </code></pre>
  
  <p>Original: (myHtml)</p>
  
  <pre><code>&lt;!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"   "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"&gt;
  &lt;html xmlns="http://www.w3.org/1999/xhtml"&gt;
  &lt;head&gt;&lt;meta http-equiv="X-UA-Compatible" content="IE=Edge" /&gt;&lt;title&gt;
       MyTitle
  &lt;/title&gt;
  </code></pre>
  
  <p>OutputHtml: (result) <strong>Notice that meta element is not closed</strong></p>
  
  <pre><code>&lt;!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"&gt;
  &lt;html xmlns="http://www.w3.org/1999/xhtml"&gt;
  &lt;head&gt;&lt;meta http-equiv="X-UA-Compatible" content="IE=Edge"&gt;&lt;title&gt;
      MyTitle
  &lt;/title&gt;
  </code></pre>
  
  <p>Similarly all input and img elements are leaved open. (Please do not answer that it should not be a problem. Well it should not be, but it is.) Chrome can not render the page correctly. Keep reading.</p>
  
  <p>What is more weird:</p>
  
  <p>Original: (myHtml)</p>
  
  <pre><code>    &lt;option value="10"&gt;Afrikaans&lt;/option&gt;
      &lt;option value="11"&gt;Albanian&lt;/option&gt;
      &lt;option value="12"&gt;Arabic&lt;/option&gt;
      &lt;option value="13"&gt;Armenian&lt;/option&gt;
      &lt;option value="14"&gt;Azerbaijani&lt;/option&gt;
      &lt;option value="15"&gt;Basque&lt;/option&gt;
  </code></pre>
  
  <p>OutputHtml: (result) <strong>Notice that that complete explicit closing tags are missing</strong></p>
  
  <pre><code>    &lt;option value="10"&gt;Afrikaans
      &lt;option value="11"&gt;Albanian
      &lt;option value="12"&gt;Arabic
      &lt;option value="13"&gt;Armenian
  </code></pre>
  
  <p>Using HtmlAgilitPack latest NuGet package: id="HtmlAgilityPack" version="1.4.9"</p>