closing in on coreutils-8.1

[Jim Meyering]

I've just pushed a few changes:

    build: do use AM_GNU_GETTEXT's "need-formatstring-macros" option
      Already discussed.  Reverts my s/need-formatstring-macros/ngettext/
      change and adds this comment:

        # As long as "grep 'PRI[diouxX]' po/*.pot" reports matches in
        # translatable strings, we must use need-formatstring-macros here.
        AM_GNU_GETTEXT([external], [need-formatstring-macros])

    tests: help-version: exit nonzero when $built_programs is empty
      This was useful to me, now that I'm using this test script in the
      diffutils package.

    tail -F can fail to track a file after it's been rotated
      I've added the test, and marked it as "expensive" so it will be
      skipped by default.  To run it, do "make check RUN_EXPENSIVE_TESTS=yes"

    true, false: perform initialization only when argc == 2
      already posted

    build: update gnulib submodule to latest

I'll do a little testing today,
make a snapshot, and see if there's any fall-out.