title: ie8 issue when dynamically adding video/audio tags
body: <p>When the page loads, I use javascript and jquery to add a set of  tags then immediately call el.mediaelementplayer() when its appened (in my case I use somenode.replaceWith(el).</p>
  
  <p>This works for all browsers so far. However when I hit a "next" button that runs the code again, I get errors on ie8:</p>
  
  <p>$node.css(...) is null or not an object : line 2696 in mediaelement-and-player.js. this is the corresponding line:</p>
  
  <pre><code>// detect 100% mode - use currentStyle for IE since css() doesn't return percentages
  if (t.height.toString().indexOf('%') &gt; 0 || t.$node.css('max-width') === '100%' || parseInt(t.$node.css('max-width').replace(/px/,''), 10) / t.$node.offsetParent().width() === 1 || (t.$node[0].currentStyle &amp;&amp; t.$node[0].currentStyle.maxWidth === '100%')) {
  </code></pre>