title: jQuery .append() not working with bootstrap icons
body: <p>I am using jQuery to dynamically insert Bootstrap Glyphicons after the text on buttons. There is an attribute <code>data-icon</code> on the <code>a</code> element, that supplies the name of the icon that is supposed to be appended to the link text. </p>
  
  <pre><code>var icon_n = $("a.btn.download").attr('data-icon');
  $("a.btn.download").append(" &lt;span class='glyphicon glyphicon-" + icon_n + "&gt;&lt;/span&gt;");
  </code></pre>
  
  <p>HTML:</p>
  
  <pre><code>&lt;a href="blog/2015/08/jquery-bootstrap-icons.download.html" class="btn btn-primary download" data-icon="download-alt"&gt;Download&lt;/a&gt;
  </code></pre>
  
  <p>As far as I know, this is supposed to insert the icon after the text. I checked the console, and there are no errors. I also checked the actual element that the icon is supposed to be set on, there is nothing there.<br>
  Why isn't this working, and how can I make it work?</p>