hgweb.cgi and hgwebdir.cgi fixes/cleanups for user configurable parts: - "import os" was missing in hgwebdir.cgi, added to comments for both script. - HGENCODING has to be set before importing hgweb, otherwise you'll get mixed encoding in changelog vs. file content/diffs. - "import sys" is only needed when changing sys.path - document purpose of cgitb.

<item>
    <title>#tag|escape#</title>
    <link>{urlbase}{url}rev/{node|short}</link>
    <description><![CDATA[#tag|strip|escape|addbreaks#]]></description>
    <pubDate>#date|rfc822date#</pubDate>
</item>