4.9 Build system
We currently use make and stepmake, which is complicated and only
used by us. Hopefully this will change in the future.
Version-specific texinfo macros
used extensively in the
WEBSITE_ONLY_BUILD version of the
website (made with ‘website.make’, used on lilypond.org)
not (?) used in the main docs?
the numbers in VERSION file: MINOR_VERSION should be 1 more than
the last release, VERSION_DEVEL should be the last online
release. Yes, VERSION_DEVEL is less than VERSION.