Add initial setuptools build system.

This commit adds the initial-pass build system for the
project.  It can be used to run tests by:

    `python3 setup.py test`

The script (and associated libraries) can be installed by typing:

    `python3 setup.py install`

Though the setup.py in this commit is functionally able to run build,
test, and install the package, it isn't without its warts:

1/ The metadata in the package setup isn't complete or ready for
   publication.
2/ A number of different setup.py tasks (PyPI publishing, etc) are
   currently untested.
3/ Test output no-longer suppresses stderr text, since the tests aren't
   being invoked directly on the command line anymore.

These should all be fixed sooner rather than later.

Issue #5