Merge branch 'maint'

Merge branch 'maint'

* maint:
  docs: don't suggest to use recursive makefile setup
  tests: fix a timestamp race in python tests
  tests: fixup: make distcheck-override-infodir pass again
  sync: update files from upstream with "make fetch"
  maint: post-release minor version bump
  release: stable release 1.12.3
  maintcheck: fix spurious warnings
  docs: fix typo: s/make install-info/make uninstall-info/
  tests: fixup: make a couple of tests executable

Signed-off-by: Stefano Lattarini <stefano.lattarini@gmail.com>