Addition of a setup.py script which can use either distutils or setuptools if available on the host system.

This merge request incorporates the addition of a new setup script which is capable of installing the package using either distutils or setuptools. Additional metadata has been added to allow the code to be packaged for PyPI.

As there was no evidence in the repository of version numbers (apologies if I missed it!) I've used the semantic versioning standard. I've also included a HISTORY.md file to include details of version changes.

The requirements list was generated using pip freeze in a virtual environment containing the API, so may be more stringent than is actually required.