revlog.py: always return tuples from parents and parentrevs
There's at least one place doing parentrevs(rev) != (rev-1, -1),
which is always true with revlog v0, since parentrevs returns a list
in this case.
#header#
<title>Mercurial repositories index</title>
</head>
<body>
<h2>Mercurial Repositories</h2>
<table>
<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 change</a></td>
<td> </td>
<tr>
#entries%indexentry#
</table>
#footer#