FYI: argv-iter: new module

[Jim Meyering]

I've just pushed the argv-iter module:
(with a few tweaks since the initial discussion),

  http://git.savannah.gnu.org/gitweb/?p=coreutils.git;a=commitdiff;h=ca738e4414

along with a test module:

  http://git.savannah.gnu.org/gitweb/?p=coreutils.git;a=commitdiff;h=d3b5555f10

and code to make coreutils use the new module:

  http://git.savannah.gnu.org/gitweb/?p=coreutils.git;a=commitdiff;h=80325aca2d

This is all in preparation for the fix for
the bug in du's --files0-from=F implementation,
which will follow soon.

wc needs a similar fix, but can benefit from having
the entire list of file names up front (alignment),
so there's a twist.