The XSL stylesheets used a mix of incorrect or outdated namespace
declarations for XHTML, probably based on ancient advice and examples.
Clean all this up.
Besides improving correctness (although probably no impact in
practice, other than possible validation failures), this removes a
bunch of useless namespace declarations in the HTML output.
Reported-by: Andres Freund <andres@anarazel.de>
Discussion: https://www.postgresql.org/message-id/flat/20220213201618.qz6p6noon3wagr3f%40alap3.anarazel.de
As before, create an INSTALL.html file for processing with lynx, but use
xsltproc and a new XSLT stylesheet instead of jade and DSSSL.
Replacing jade with xsltproc removes jade from the requirements for
distribution building.
Reviewed-by: Magnus Hagander <magnus@hagander.net>