Bump Data::Dumper to 2.173 (no real change):

Bump Data::Dumper to 2.173 (no real change):

The change will happen in the Makefile.PL which is generated and
released. It is generated automatically, so we can't actually inject
the parts that we want.

The way I handle it at the moment is:

* Build perl
* Copy Data::Dumper to other directory
* Grab MANIFEST.SKIP and Makefile.PL from previous release
* Add the DEFINE we need to fix this:

    # In WriteMakefile(...)
    DEFINE        => '-DUSE_PPPORT_H',

* perl Makefile.PL && make && make test && make dist
* Retest the tarball
* Release to CPAN

But we need this bump anyway, so this commit.