title: queue() call d3.json of world-110m.json produces syntax error for a worldmap with topoJSON
body: <p>I successfully completed <a href="http://bost.ocks.org/mike/map/" rel="nofollow">the "Let's make a map" tutorial</a> and now want to <a href="http://techslides.com/d3-world-maps-tooltips-zooming-and-queue/" rel="nofollow">make a world map</a>. However, all examples I tried (a couple from mbostock) only display background graphics in chrome and firefox. I get the following error in firebug:</p>
  
  <p>SyntaxError: JSON.parse: unexpected character   </p>
  
  <p>return JSON.parse(request.responseText);</p>
  
  <p>in d3.v3.js but I assume it starts with the following code in the index.htm:</p>
  
  <pre><code>queue()
  .defer(d3.json, "world-110m.json")
  .defer(d3.tsv, "world-country-names.tsv")
  .await(ready); 
  </code></pre>
  
  <p>The call d3.json of "world-110m.json" seems to produce the error. I have found nothing about this error on the internet -- I'd appreciate some help.</p>