highlight: only pygmentize for HTML mimetypes
For non-html mimetypes it doesn't make much sense. This also fixes the
issue that highlight unconditionally adds a <link/> tag for its CSS to
the template's header (which is pointless in text/plain output).
#header#
<title>#repo|escape#: changelog</title>
<link rel="alternate" type="application/atom+xml"
href="#url#atom-log" title="Atom feed for #repo|escape#">
<link rel="alternate" type="application/rss+xml"
href="#url#rss-log" title="RSS feed for #repo|escape#">
</head>
<body>
<div class="buttons">
<a href="#url#shortlog/#rev#{sessionvars%urlparameter}">shortlog</a>
<a href="#url#graph{sessionvars%urlparameter}">graph</a>
<a href="#url#tags{sessionvars%urlparameter}">tags</a>
<a href="#url#file/#node|short#{sessionvars%urlparameter}">files</a>
#archives%archiveentry#
<a type="application/rss+xml" href="#url#rss-log">rss</a>
<a type="application/atom+xml" href="#url#atom-log" title="Atom feed for #repo|escape#">atom</a>
</div>
<h2>changelog for #repo|escape#</h2>
<form action="#url#log">
{sessionvars%hiddenformentry}
<p>
<label for="search1">search:</label>
<input name="rev" id="search1" type="text" size="30">
navigate: <small class="navigate">#changenav%naventry#</small>
</p>
</form>
#entries%changelogentry#
<form action="#url#log">
{sessionvars%hiddenformentry}
<p>
<label for="search2">search:</label>
<input name="rev" id="search2" type="text" size="30">
navigate: <small class="navigate">#changenav%naventry#</small>
</p>
</form>
#footer#