Replace IIM references with DXG

www/templates/local-footer.tpl.php

 <nav id="dcf-footer-group-1" role="navigation" aria-labelledby="dcf-footer-group-1-heading">
   <h3 class="dcf-txt-md dcf-bold dcf-uppercase dcf-lh-3 unl-ls-2 unl-cream" id="dcf-footer-group-1-heading">About UNL Search</h3>
-  <p>This application is a product of the <a href="https://iim.unl.edu/">Internet and Interactive Media group at Nebraska</a>. IIM is a partnership of <a href="https://ucomm.unl.edu/">University Communication</a> and <a href="https://its.unl.edu/">Information Technology Services</a>.</p>
+  <p>This application is a product of the <a href="https://dxg.unl.edu/">Digital Experience Group at Nebraska</a>. DXG is a partnership of <a href="https://ucomm.unl.edu/">University Communication</a> and <a href="https://its.unl.edu/">Information Technology Services</a>.</p>
     <?php
       // TODO: Verify file will continue to exist and correct
       echo file_get_contents('http://www.unl.edu/ucomm/sharedcode/footerContactInfo.html');