Merge remote-tracking branch 'origin/maint'

Merge remote-tracking branch 'origin/maint'

* origin/maint:
  skeletons: factor yacc.c and glr.c.
  glr.c: minor refactoring.
  tests: remove all the -On flags.
  maint: fix spello.
  maint: improve release procedure instructions.
  gnulib: update readme-release.
  maint: cfg.mk: manual title.
  maint: cfg.mk: simplify
  maint: post-release administrivia

Conflicts:
	NEWS
	bootstrap.conf