Rework setup.py to use distutils instead of setuptools.

Rework setup.py to use distutils instead of setuptools.

I'm not super happy about this step, but here are the pros and cons:
+ Include ebuild.tmpl in distribution  (`issue 11`_)
+ Remove setuptools dependency
- Implement test command by hand

setuptools also supports package_data, but I couldn't find an
incantation that included ebuild.tmpl.  The distutils incantation is
simple enough.

.. _issue 11: http://code.google.com/p/g-pypi/issues/detail?id=11