#427 man: add support for orderedlist's enumeration attribute

[Ori Avtalion]

The current manpage xsl ignores the 'numeration' attribute on <orderedlist>, such as <orderedlist numeration="loweralpha">, and always assumes numeration="arabic".

It will be nice to have support for other numerations, since sometimes text refers back to sections which do not exist, e.g. "see section b.2" when only 2.2 exists.