hgweb: show ages in repos' Last modified column in monoblue and gitweb

Index page, which shows the list of available repositories, has a column where
the last modification date for each repo is shown. paper, coal and spartan
already show the dates in relative format (e.g. "2 weeks ago"), because these
styles have the required process_dates() js function call in their footer
templates, which are included on every page. But monoblue and gitweb styles
have more things in the footer templates, such as repo name and its atom/rss
links, so they don't include the footer on index page (as this page doesn't
have a single repo context).

Let's call process_dates() without including the footer.

mercurial/templates/gitweb/index.tmpl

@@ -22,5 +22,6 b''
 <div class="page_footer">
 {motd}
 </div>
+<script type="text/javascript">process_dates()</script>
 </body>
 </html>

mercurial/templates/monoblue/index.tmpl

@@ -35,5 +35,6 b''
     <div id="corner-bottom-right"></div>
 
 </div>
+<script type="text/javascript">process_dates()</script>
 </body>
 </html>