title: RSS Not Validating with spaces in CDATA
body: <p>I have a third party app creating RSS XML. There are spaces within the CDATA text, that makes validation fail.</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
  &lt;rss version="2.0"&gt;
  &lt;channel&gt;
  &lt;title&gt;Title&lt;/title&gt;
  &lt;link&gt;http://www.example.com/&lt;/link&gt;
  &lt;description&gt;Description&lt;/description&gt;
  &lt;image&gt;
      &lt;title&gt;Title&lt;/title&gt;
      &lt;url&gt;&lt;![CDATA[http://www.example.com/some image/image.jpg]]&gt;&lt;/url&gt;
      &lt;link&gt;http://www.example.com/&lt;/link&gt;
  &lt;/image&gt;
  &lt;item&gt;
      &lt;title&gt;Item title&lt;/title&gt;
      &lt;link&gt;http://www.example.com/&lt;/link&gt;
      &lt;description&gt;Description&lt;/description&gt;
  &lt;/item&gt;
  &lt;/channel&gt;
  &lt;/rss&gt;
  </code></pre>
  
  <p>I don't have control over the CDATA enclosed text. But I can confirm the URL in question takes me to the image when visited directly from a browser. The error I get is <code>Invalid character in a URI</code>, and when I manually edit the file on the server to remove the space the RSS validates.</p>
  
  <p>Encoding the space <code>%20</code> seems to work. But I'm not sure how to do this ongoing. Could I change the XML output to be PHP perhaps and have the url encoded by the server when it's loaded?</p>