title: How to make js-generated xml file be in utf-8
body: <p>I generate some xml in-browser and set it as data-uri for a link.
  When I click the link it is opened, but contents is recognized as ASCII and the text is garbled.</p>
  
  <p>How do I make the content of the generated file be utf-8?</p>
  
  <p>The xml starts with prolog <code>&lt;?xml version="1.0" encoding="utf-8" ?&gt;</code> but this doesn't help.</p>