title: Feature-detect: mutation-event availability in JavaScript?
body: <p>How can my JavaScript detect if an event is available?  </p>
  
  <p>I'm aware of some great <a href="http://quirksmode.org/dom/events/index.html" rel="nofollow noreferrer">event-compatibility tables</a>, but I need to use feature detection, not browser-sniffing plus a lookup table.</p>
  
  <p>Specifically, my JS makes great use of the DOM mutation events (<code>DOMNodeInserted</code> and <code>DOMSubtreeModified</code>) -- which work great in all browsers except (of course) Internet Explorer.</p>
  
  <p>So, how would I detect if a browser supports <code>DOMNodeInserted</code>?</p>