Fix packaging; support Python 3 and Python 2 in a single codebase

This is great software! But you are not yet familiar with Python 3 compatibility and Python packaging in general.

Here I provide Python 3 compatibility using the *nine* library. Tests pass on Python 2.6, 2.7 and 3.3. Probably 3.2 too because I took care of unicode literals.

Please consider setting up travis-ci so you can more easily keep these Python versions working.

About packaging: The current version cannot be easy_installed. It says:

    error: Couldn't find a setup script in /tmp/easy_install-LmAZGR/grimace-0.0.10.linux-x86_64.tar.gz

That error is fixed in this pull request.

In the future, do not create binary distributions, they are not needed. Use only setup.py sdist upload