Merge branch 'maint'

Merge branch 'maint'

* maint:
  configure: remove an obsolete TODO comment
  post-release: micro version bump (1.13.3a)
  release: stable micro release 1.13.3
  typofix: fix grammaro in comments in t/tags-pr12372.sh
  NEWS: minor fixlets, re-wording, and better text wrapping
  tests: slightly stricter checks in t/cxx-demo.sh
  tests: fix spurious failure when 'etags' program is Exuberant Ctags
  tests: fix spurious failure due to missing sleeps
  maint: version bump after beta release 1.13b
  release: beta release 1.13b (will become 1.14)
  maint: support new Automake versioning scheme in tagging/uploading rules
  announcement: can be generated from development snapshots as well
  announcement: can be generated from development snapshots as well
  announcement: be less strict in the paring of NEWS
  maint: version bump after beta release 1.13.2b
  release: beta release 1.13.2b (will become 1.13.3)
  sync: update config.guess from upstream
  automake: assume we can always pass '-o' to the C compiler
  NEWS: document recent testsuite fixes (MinGW/MSYS related)
  depcomp: avoid trailing backslash in depfile for depmode=msvc7
  tests: prune some weed in a non-POSIX test
  tests: avoid a spurious failure on MSYS
  t/README: document "run_make", discourage "make -e"
  cosmetics: tiny whitespace fixlets
  tests: avoid a spurious failure with MSVC
  tests: avoid a spurious failure on non-POSIX systems

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