Merge branch 'maint'

Merge branch 'maint'

* maint:
  cosmetics: move CheckListOfTests.am into tests/
  tests: move all under the same hierarchy ('tests/' directory)
  gitlog-to-changelog: update from upstream
  changelog: don't cluster multiple entries under the same "date line"

+ Extra non-trivial edits:

* tests/Makefile.am (XFAIL_TESTS): Update with the xfailing tests
that were in 'lib/Automake/tests'.  Add proper "FIXME" comment.