Various changes

- Removed short readme
- setup.py contains the short description
- Removed distribute_setup.py to use a normal setup.py
- setup.py uses distutils (more standard)
- ColorMap.py automatically converts to str. This is done because it's error prone otherwise to try to join together unicode and str, and in py3 there is no unicode type. So instead of raising an exception it attempts to do it and in most cases it will work, and in case of non-ascii unicode will raise an exception but to keep py3 compatibility I suppose that's a price to pay.