title: DC.js | How can i get .title (tooltip) to work on boxplot?
body: <p>I have a number of boxplots on a time x axis. I've switched off brushing, because I want the tooltip (.title) to work instead. However it's not working. Grateful for any suggestions! Here's my code:</p>
  
  <pre><code>distTime.width(350)
          .height(150)
          .margins({left:50,right:10,top:0,bottom:30})
          .dimension(timeDim)
          .group(premiumGroup)
          .clipPadding(30)
          .brushOn(false)
          .renderTitle(true)
          .title(function(d){ return "emma"; })
          .boxWidth(20)
          .colors("steelblue")
          .renderHorizontalGridLines(true)
          .x(d3.time.scale())
          .round(d3.time.years.round)
          .xUnits(d3.time.years)
          .elasticY(true);
  
      distTime.yAxis().tickFormat(d3.format('s'));
      distTime.yAxis().ticks(5);
  
  function calc_domain(chart) {
      var min = d3.min(chart.group().all(), function(kv) { return kv.key; }),
          max = d3.max(chart.group().all(), function(kv) { return kv.key; });
      //max = d3.time.year.offset(max, 1);
      chart.x().domain([min, max]);
  }
  distTime.on('preRender', calc_domain);
  distTime.on('preRedraw', calc_domain);
  </code></pre>