title: Blank placeholder for bootstrap glyphicon
body: <p>I have a table with sorting bootstrap glyphicons in the header.  The icon is only shown if the table is being sorted by that particular header.  When I click the cell, it changes the sizing of the table.  The table is dynamic, so I'd prefer not fixing the cell sizes.  Is there a way I can put a placeholder in there that takes the place of the glyphicon?</p>
  
  <p>I know how the javascript will work to hide it, I just don't know how to do the css to give the span some size.</p>
  
  <p>(this is bootstrap 3.0 btw)...</p>
  
  <pre><code>&lt;span class="glyphicon glyphicon-arrow-down"&gt;&lt;span&gt;
  </code></pre>
  
  <p>is the particular icon.  Chrome says that it's 16px wide when displayed.  </p>
  
  <p>The actual project is a little more complicated, here's a plunkr:</p>
  
  <p><a href="http://plnkr.co/edit/N6nkW3e4gDdpQdtRC8ue?p=preview" rel="noreferrer">http://plnkr.co/edit/N6nkW3e4gDdpQdtRC8ue?p=preview</a></p>