title: jQuery :contains selector to search for multiple strings
body: <p>Assuming i have:</p>
  
  <pre><code>&lt;li id="1"&gt;Mary&lt;/li&gt;
  &lt;li id="2"&gt;John, Mary, Dave&lt;/li&gt;
  &lt;li id="3"&gt;John, Dave, Mary&lt;/li&gt;
  &lt;li id="4"&gt;John&lt;/li&gt;
  </code></pre>
  
  <p>If i need to find all &lt;li&gt; Elements which contain "John" and "Mary", how would i construct the jQuery?</p>
  
  <p>A search for a single string seems easy:</p>
  
  <pre><code>$('li:contains("John")').text()
  </code></pre>
  
  <p>I am looking for something like the following pseudo code:</p>
  
  <pre><code>$('li:contains("John")' &amp;&amp; 'li:contains("Mary")').text()
  </code></pre>
  
  <p>Thanks!</p>