hgweb: urlescape all urls, HTML escape repo/tag/branch/... names
Without this, repository paths or names containing e.g. & characters or html
tags yielded strange results, possibly allowing cross-site scripting attacks.
<entry>
<title>{branch|escape}</title>
<link rel="alternate" href="{urlbase}{url|urlescape}rev/{node|short}"/>
<id>{urlbase}{url|urlescape}#branch-{node}</id>
<updated>{date|rfc3339date}</updated>
<published>{date|rfc3339date}</published>
<content type="text"><![CDATA[{branch|strip|escape|addbreaks}]]></content>
</entry>