Before doing the following changes done by hand, I also ran ‘make
update-copyright’ and ‘config/srclist-update <config/srclist.txt’
to do most of the copyright years automatically. A few upstream
sources are still in 2019 but these should eventually be changed
automatically too.
* build-aux/declared.sh (func_version):
* build-aux/libtool-next-version (func_version):
* build-aux/run-test (func_version):
Update these notices by hand. Put just the last year
in output of programs, as per GNU coding standards.