Clean up date and timezone handling.
We used to pass changelog dates around as a "unixtime timezone" string
containing a pair of encoded ints. Now, they get passed around as a
(unixtime, timezone) tuple of numbers, which makes much more sense.
#header#
<title>#repo|escape#: #file# history</title>
<link rel="alternate" type="application/rss+xml"
href="?cmd=filelog;file=#file#;filenode=0;style=rss" title="RSS feed for #repo|escape#:#file#">
</head>
</head>
<body>
<div class="buttons">
<a href="?cmd=changelog">changelog</a>
<a href="?cmd=tags">tags</a>
<a href="?cmd=file;file=#file#;filenode=#filenode#">file</a>
<a href="?cmd=annotate;file=#file#;filenode=#filenode#">annotate</a>
<a type="application/rss+xml" href="?cmd=filelog;file=#file#;filenode=0;style=rss">rss</a>
</div>
<h2>#file# revision history</h2>
#entries%filelogentry#
#footer#