title: Wrap searched term without affecting uppercase/lowercase
body: <p>How do I wrap tags around a search term and keep the original uppercase/lowercase phrase?</p>
  
  <p>So I have this code:</p>
  
  <pre><code>$text = 'Hello world';
  $search = 'hello';
  $text = str_ireplace($search, '&lt;span&gt;' . $search . '&lt;/span&gt;', $text);
  echo $text; 
  </code></pre>
  
  <p>This results with:</p>
  
  <pre><code>&lt;span&gt;hello&lt;/span&gt; world
  </code></pre>
  
  <p>While I want it to keep original letter case. So:</p>
  
  <pre><code>&lt;span&gt;Hello&lt;/span&gt; world
  </code></pre>
  
  <p>How do I do this?</p>