dagop: comment why revancestors() doesn't heapify input revs at once
I wondered why we're doing this complicated stuff without noticing the input
revs may be iterated lazily in descending order.
c1f666e27345 showed why.
{header}
<title>Mercurial repository not found</title>
</head>
<body>
<h2>Mercurial repository not found</h2>
The specified repository "{repo|escape}" is unknown, sorry.
Please go back to the <a href="{url|urlescape}">main repository list page</a>.
{footer}