pip install

Adds setup.py file to allow installing with pip. 

You can now install straight from github with:
pip install git+https://github.com/zingbretsen/RyMVPA.git
or
pip install git+https://github.com/rystoli/RyMVPA.git (should you choose to merge the patch)

Also removes plotter.py, which looked Freelab-lab-specific