title: Why is brunch adding in this requirejs code?
body: <p>I have a file <code>app/js/d3.js</code> in a brunch project that uses requirejs. When I build the file, the code in <code>app/js/d3.js</code> is concatenated into <code>app.js</code> as expected. But it is wrapped in what looks like some require code, as follows: </p>
  
  <pre><code>require.register("js/d3", function(exports, require, module) { #this wrapper is added
  window.onload = function() { #then there is the start of code from app/js/d3.js
  </code></pre>
  
  <p>I am new enough to require that I can't tell if this is supposed to happen or if this is unintended behavior from Brunch. When I search the <a href="http://requirejs.org/docs/api.html" rel="nofollow">require api</a> for register I don't see a register method. </p>
  
  <p>What's going on? Why is my code getting wrapped this way? My config.coffee looks like this:</p>
  
  <pre><code>  files:
      javascripts:
        joinTo:
          "js/app.js": /^app/
          "js/vendor.js": /^(bower_components|vendor)/
        order:
          before: [
            'bower_components/queue-async/queue.js',
            'bower_components/topojson/topojson.js',
            'bower_components/topojson/topojson.js',
            'bower_components/d3/d3.js',
            'bower_components/requirejs/requirejs.js'
          ]
  </code></pre>