title: Reg expression to remove empty Tags (any of them)?
body: <p>I like to remove <strong>any</strong> empty html tag which is empty or containing spaces.</p>
  
  <p>something like to get:</p>
  
  <pre><code>$string = "&lt;b&gt;text&lt;/b&gt;&lt;b&gt;&lt;span&gt; &lt;/span&gt;&lt;/b&gt;&lt;p&gt;  &lt;br/&gt;&lt;/p&gt;&lt;b&gt;&lt;/b&gt;&lt;font size='4'&gt;&lt;/font&gt;";
  </code></pre>
  
  <p>to: </p>
  
  <pre><code>$string ="&lt;b&gt;text&lt;/b&gt;=;
  </code></pre>