title: Ractive.js preventDefault events on event proxies
body: <p>Lets say I have the following code:</p>
  
  <p><strong>template</strong></p>
  
  <pre><code>&lt;a on-click='myfunc' href="#"&gt;Activate!&lt;/button&gt;
  </code></pre>
  
  <p><strong>javascript</strong></p>
  
  <pre><code>var ractive = new Ractive({
    el: output,
    template: template
  });
  
  ractive.on( 'myfunc', function ( event ) {
    alert( 'Hello world!' );
    ?????? --&gt; how to prevent the next click event from the a href?
  });
  </code></pre>
  
  <p>How can I prevent the next click event from the a href, from the javascript code?
  I tried event.preventDefault(); but the object has no method 'preventDefault'</p>