My previous implementation only used the configure step from autoconf.
Technically in this case it should have been enough, but it’s also kind
of an abuse of the tools, it was meant to have another stage.  This uses
the tools as they were designed, which in my history with autoconf is
always easier to maintain.  Also it gives us the option of using more
features or doing more fancy things in an install step without the
standalone versions being out of sync from system installed versions.

The number of options that needed to be set to get a proper standalone
build is fairly large. Given that it was already repeated twice in
different CI contexts it occurred to me the whole batch of settings
should just be one preset so that people can build their own standalone
version easily from the source tarball if they want.

Co-authored-by: Richard Hartmann <[email protected]>