Refactored to Master - Githubissues

I think I can merge this in now. No work is being done on the old master branch any more.

This completely changes the entire thing.

The single file is split up into a number of new modules relating to different APIS:
- people.py contains the People API, as well as a couple of bits from other APIs that relate to people.
- contacts.py contains the People Contacts API
- lists.py contains the Lists API.
- tags.py contains the People Tags API.

These all inherit basic functionality (response checking, authorisation etc.) from nb_api.py

Also there is a nationbuilder.py module that should be used as an entry point for using nbpy.

nikr / nbpy