title: Remove useless paragraph tags from string
body: <p>If I have a string like:</p>
  
  <pre><code>&lt;p&gt;&amp;nbsp;&lt;/p&gt;
  &lt;p&gt;&lt;/p&gt;
  &lt;p class="a"&gt;&lt;br /&gt;&lt;/p&gt;
  &lt;p class="b"&gt;&amp;nbsp;&lt;/p&gt;
  &lt;p&gt;blah blah blah this is some real content&lt;/p&gt;
  &lt;p&gt;&amp;nbsp;&lt;/p&gt;
  &lt;p&gt;&lt;/p&gt;
  &lt;p class="a"&gt;&lt;br /&gt;&lt;/p&gt;
  </code></pre>
  
  <p>How can I turn it into just:</p>
  
  <pre><code>&lt;p&gt;blah blah blah this is some real content&lt;/p&gt;
  </code></pre>
  
  <p>The regex needs to pick up <code>&amp;nbsp;</code>s and spaces.</p>