new snapshot (rm fixes and new program: mktemp)

[Jim Meyering]

In addition to adding mktemp, I've fixed a few low-probability bugs in rm.
This also includes a lot of new code from gnulib, by virtue of coreutils
now requiring the vasprintf-posix module (mostly for non-POSIX systems),
so please give this a work-out if you haven't built a snapshot recently:

    http://meyering.net/cu/coreutils-6.9-ss.tar.gz
    http://meyering.net/cu/coreutils-6.9-ss.tar.gz.sig

aka

    http://meyering.net/cu/coreutils-6.9-316-e6f4b.tar.gz
    http://meyering.net/cu/coreutils-6.9-316-e6f4b.tar.gz.sig

In addition, note that the next snapshot will probably be compressed
with lzma, rather than with gzip.  The resulting file is less than half
the size of the .gz one and it is even 2MB smaller than the .bz2 one:

    $ du -sh coreutils-6.9*
    8.4M    coreutils-6.9-316-e6f4b-dirty.tar.gz
    3.5M    coreutils-6.9-316-e6f4b-dirty.tar.lzma

So, since uploads rarely get better than 2x speed-up with the
rsyncable-gzip'd tarballs, I'd just as soon use the better
compression program.