title: Usemin not replacing reference blocks in HTML
body: <p>I can see css and js files correctly getting concatenated, revved and copied to the correct folder. The last step though, being usemin replacing the blocks and images in html file, is not working for some reason. The image references in the css file do get replaced.</p>
  
  <p>Gruntfile.js:</p>
  
  <pre><code>useminPrepare: {
    html: '&lt;%= yeoman.app %&gt;/index.html',
    options: {
      dest: '&lt;%= yeoman.dist %&gt;'
    }
  },
  
  // Performs rewrites based on rev and the useminPrepare configuration
  usemin: {
    css: ['&lt;%= yeoman.dist %&gt;/styles/{,*/}*.css'],
    html: ['&lt;%= yeoman.dist %&gt;/{,*/}*.html'],
    options: {
      assetsDirs: ['&lt;%= yeoman.dist %&gt;/images', '&lt;%= yeoman.dist %&gt;/styles', '&lt;%= yeoman.dist %&gt;/scripts']
    }
  },
  </code></pre>
  
  <p>in Html I have:</p>
  
  <pre><code>&lt;!-- build:css styles/main.css --&gt;
  &lt;link rel="stylesheet" href="Styles/main.css"&gt;
  &lt;link rel="stylesheet" href="Shared/Styles/default.css"&gt;
  &lt;link rel="stylesheet" href="Shared/Styles/default.date.css"&gt;
  &lt;link rel="stylesheet" href="Shared/Styles/default.time.css"&gt;
  &lt;!-- endbuild --&gt;
  </code></pre>
  
  <p>The output when building says:</p>
  
  <pre><code>[1mProcessing as HTML - dist/index.html[22m
  Update the HTML to reference our concat/min/revved script files
  Update the HTML with the new css filenames
  Update the HTML with the new img filenames
  Update the HTML with data-main tags
  Update the HTML with data-* tags
  Update the HTML with background imgs, case there is some inline style
  Update the HTML with anchors images
  Update the HTML with reference in input
  </code></pre>
  
  <p>The file structure in dist:</p>
  
  <pre><code>– dist
     |– index.html
     |– styles
        |– 146eba12.main.css
     |– scripts
       |– ...
     |– images
       |– ...
  </code></pre>
  
  <p>This has been driving me crazy and I cannot figure out why. Any assistance will be highly appreciated.</p>
  
  <p>UPDATE: In a further development, and I don't know why, the blocks in html now are replaced by one line pointing to the concatenated file but it does not prepend the hash added during revving. So it does:</p>
  
  <pre><code>&lt;link rel="stylesheet" href="styles/main.css"/&gt;
  </code></pre>
  
  <p>Rather than:</p>
  
  <pre><code>&lt;link rel="stylesheet" href="styles/b64b6f59.main.css"/&gt;
  </code></pre>