Move .gitignore to the top-level directory.

The git project's top-level .gitignore already ignores "*.py[co]", so
a .gitignore file will not be needed if it is integrated into that
project.
Improve the summary of the project in README.
Add a minimal setup.py.

Also add some entries for packaging outputs to .gitignore.
Add MANIFEST.in file.
Add classifiers and keywords.
Use the README file as the long description.
Merge branch 'python-packaging'

Add some infrastructure to allow the project to be registered with
PyPI and installed using distutils et al.