title: BundleTransformer.Core throwing implementation exception
body: <p>I'm trying to use <code>BundleTransformer.Core</code> and <code>BundleTransformer.Less</code>, however I've run into the following exception when trying to setup MVC4 bundles using the recommended code:</p>
  
  <blockquote>
    <p>Method 'OrderFiles' in type 'BundleTransformer.Core.Orderers.NullOrderer' does not have an implementation.</p>
  </blockquote>
  
  <p>That exception is thrown on registering the following:</p>
  
  <pre><code>public static void RegisterBundles(BundleCollection bundles)
  {
      var cssTransformer = new CssTransformer();
      var jsTransformer = new JsTransformer();
      var nullOrderer = new NullOrderer();
  
      var commonStylesBundle = new Bundle("~/Bundles/CommonStyles");
      commonStylesBundle.Include("~/Styles/V3/functions.less",
                                 "~/Styles/V3/helpers.less",
                                 "~/Styles/V3/media-queries.less",
                                 "~/Styles/V3/normalize.less",
                                 "~/Styles/V3/print.less",
                                 "~/Styles/V3/style.less");
      commonStylesBundle.Transforms.Add(cssTransformer);
      commonStylesBundle.Orderer = nullOrderer;
  
      bundles.Add(commonStylesBundle);
  }
  </code></pre>
  
  <p>I have tried both the latest versions of <code>BundleTransformer.Core</code> and the immediate prior version.</p>