hgweb: call process_dates() via DOM event listener
All the hgweb templates include mercurial.js in their header. All
the hgweb templates have the same <script> boilerplate to run
process_dates(). This patch factors that function call into
mercurial.js as part of a DOMContentLoaded event listener.
{header}
<title>Mercurial repositories index</title>
</head>
<body>
<div class="page_header">
<a href="{logourl}" title="Mercurial" style="float: right;">Mercurial</a>
<a href="/">Mercurial</a> {pathdef%breadcrumb}
</div>
<table cellspacing="0">
<tr>
<td><a href="?sort={sort_name}">Name</a></td>
<td><a href="?sort={sort_description}">Description</a></td>
<td><a href="?sort={sort_contact}">Contact</a></td>
<td><a href="?sort={sort_lastchange}">Last modified</a></td>
<td> </td>
<td> </td>
</tr>
{entries%indexentry}
</table>
<div class="page_footer">
{motd}
</div>
</body>
</html>