title: Issue with appending items in jQuery Masonry
body: <p>I'm trying to do a masonry layout with a bunch of tiles with some containing images. Here's roughly my code:</p>
  
  <pre><code>var $mainContent = $('#main-content');
  
  $mainContent.imagesLoaded(function() {
    $mainContent.masonry()
  });
  
  loadMore = function() {
    $.ajax({
      url: '/things',
      success: function (data) {
        var $data = $(data);
        $data.imagesLoaded(function() {
          $mainContent.append($data).masonry('appended', $data, true)
        })
      }
    })
  }
  
  $('#load-more').on('click', loadMore)
  </code></pre>
  
  <p>However, when I run this, I get the following error in Chrome's console:</p>
  
  <pre><code>Uncaught TypeError: Cannot read property 'width' of undefined
  </code></pre>
  
  <p>Trace:</p>
  
  <pre><code>bB jquery.min.js:2
  f.each.f.cssHooks.(anonymous function).get jquery.min.js:4
  f.extend.css jquery.min.js:4
  f.each.f.fn.(anonymous function) jquery.min.js:4
  e.extend.access jquery.min.js:2
  f.each.f.fn.(anonymous function) jquery.min.js:4
  f.each.f.fn.(anonymous function) jquery.min.js:4
  $.Mason._placeBrick jquery.masonry.js:246
  $.Mason.layout jquery.masonry.js:172
  $.Mason._appended jquery.masonry.js:352
  $.Mason.appended jquery.masonry.js:341
  </code></pre>
  
  <p>I'm using Masonry v.2.1.05 and jQuery v1.7.2</p>
  
  <p>However, when I instead do <code>reload</code> instead of <code>appended</code>, it works like it does in the demos, but I want the posts to be populated from the bottom, and I don't want all the posts to be recalculated.</p>
  
  <p>Do you know what's going on?</p>
  
  <p>I also put this issue on <a href="https://github.com/desandro/masonry/issues/213" rel="nofollow">github</a> but I haven't gotten a response yet.</p>