Refactoring: Write a Version Comparison Program

        $ perl ~/gitwork/myscripts/compare_git_versions/compare_git_versions \
        >         --workdir=/home/jkeenan/gitwork/list-compare \
        >         --program=/home/jkeenan/learn/perl/lc/get_3_intersection.pl \
        >         --before=v0.38 \
        >         --after=v0.51 \
        >         --tests-only

        HEAD is now at daa3559... Update support information.  v0.38.
        ok 1 - Running tests only
        List::Compare::Functional version: 0.38000
        ok 2 - Got expected intersection
        1..2
        Previous HEAD position was daa3559... Update support information.  v0.38.

        HEAD is now at e565fb3... CPAN version 0.51.
        ok 1 - Running tests only
        List::Compare::Functional version: 0.51000
        ok 2 - Got expected intersection
        1..2