title: d3 contextmenu not firing
body: <p>I'm just adding bootstrap and jquery to my d3 script.  It's mostly working, but I notice that I'm no longer getting right-click / contextmenu events.  My setup code looks like this:</p>
  
  <pre><code>this.svg_canvas = d3.select("#" + this.container_id)
    .append("svg")
    .attr("width", this.width)
    .attr("height", this.height)
    .on("click", this._selectNodes.bind(this))
    .on("mousedown", this._handleMouseDown.bind(this))
    .on("contextmenu", function(data, index) { graph_view._showContextMenu(data, index); })
    .call(this.zoom_behavior.bind(this))
  ;
  </code></pre>
  
  <p>It's worth mentioning that all other gestures -- click, mousedown, and zoom -- appear to be working just fine.</p>
  
  <p>Any ideas of where to look or how to debug this?</p>