Bring back 'View Source' on php.net

Author: sgolemon

include/footer.inc

@@ -68,6 +68,9 @@
         <li><a href="/contact.php">Contact</a></li>
         <li><a href="/sites.php">Other PHP.net sites</a></li>
         <li><a href="/privacy.php">Privacy policy</a></li>
+<?php if (!empty($_SERVER['BASE_PAGE'])): ?>
+        <li><a href="https://github.com/php/web-php/blob/master/<?php echo urlencode($_SERVER['BASE_PAGE']); ?>">View Source</a></li>
+<?php endif; ?>
       </ul>
       </div>
     </div>