occurrences of PACKAGE_COPYRIGHT_YEAR in configure.ac.
** Update NEWS, commit and tag.
-See do-release-commit-and-tag in README-release.
+See do-release-commit-and-tag in README-release. For a while, we used
+beta names such as "2.6_rc1". Now that we use gnulib in the release
+procedure, we must use "2.5.90", which has the additional benefit of
+being properly sorted in "git tag -l".
** make alpha, beta, or stable
See README-release.