title: Draw a slash line over glyphicon or font-awesome icon using CSS
body: <p>I would like to draw a slash line over a glyph icon or an icon from font-awesome.
  For example, I want to put slash over this icon as "no wifi available.</p>
  
  <pre><code>&lt;i class="fa fa-signal"&gt;&lt;/i&gt;
  </code></pre>
  
  <p>I tried to do it with stacking but for that I would need an one icon that is a slash.</p>
  
  <pre><code>&lt;div class="fa-stack fa-lg"&gt;
      &lt;i class="fa fa-signal fa-stack-1x"&gt;&lt;/i&gt;
      &lt;i class="fa fa-ban fa-stack-2x text-danger"&gt;&lt;/i&gt;                
  &lt;/div&gt;
  Wi-Fi
  </code></pre>
  
  <p>Is there an easier way to have a slash over the signal icon?</p>