title: Extract and add link to URLs in string
body: <p>I have several strings that have links in them. For instance:</p>
  
  <pre><code>var str = "I really love this site: http://www.stackoverflow.com"
  </code></pre>
  
  <p>and I need to add a link tag to that so the str will be:</p>
  
  <pre><code>I really love this site: &lt;a href="http://www.stackoverflow.com"&gt;http://www.stackoverflow.com&lt;/a&gt;
  </code></pre>