hgweb: changenav: separate pages before and after the current position
This should allow styles to customize more precisely navigation bar,
for example inserting a cursor to show where we are in the navigation bar.
{header}
<title>{repo|escape}: {file|escape} history</title>
<link rel="alternate" type="application/atom+xml"
href="{url}atom-log/tip/{file|urlescape}" title="Atom feed for {repo|escape}:{file}">
<link rel="alternate" type="application/rss+xml"
href="{url}rss-log/tip/{file|urlescape}" title="RSS feed for {repo|escape}:{file}">
</head>
<body>
<div class="buttons">
<a href="{url}log{sessionvars%urlparameter}">changelog</a>
<a href="{url}shortlog{sessionvars%urlparameter}">shortlog</a>
<a href="{url}graph{sessionvars%urlparameter}">graph</a>
<a href="{url}tags{sessionvars%urlparameter}">tags</a>
<a href="{url}branches{sessionvars%urlparameter}">branches</a>
<a href="{url}file/{node|short}/{file|urlescape}{sessionvars%urlparameter}">file</a>
<a href="{url}annotate/{node|short}/{file|urlescape}{sessionvars%urlparameter}">annotate</a>
<a type="application/rss+xml" href="{url}rss-log/tip/{file|urlescape}">rss</a>
<a type="application/atom+xml" href="{url}atom-log/tip/{file|urlescape}" title="Atom feed for {repo|escape}:{file}">atom</a>
</div>
<h2>{file|escape} revision history</h2>
<p>navigate: <small class="navigate">{nav%filenav}</small></p>
{entries%filelogentry}
{footer}