Update CONTRIBUTORS.rst
Add function to convert between number bases.
Add support for arbitrary radius and base.
Use uint64 always, for now.
Fix python update rule to handle arbitrary radius and base.
Update cython code for evolving CAs.
Merge branch 'master' of github.com:ComSciCtr/pycelle
Update README.rst

New demo image.
Update README.rst
Add a random_ECA class method.
Merge branch 'master' of github.com:ComSciCtr/pycelle