The XSL stylesheets used a mix of incorrect or outdated namespace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
All documentation is now built using XSLT. Remove all references to
Jade, DSSSL, also JadeTex and some other outdated tooling.
For chunked HTML builds, this changes nothing, but removes the
transitional "oldhtml" target. The single-page HTML build is ported
over to XSLT. For PDF builds, this removes the JadeTex builds and moves
the FOP builds in their place.