Fix:  Unknown distribution option: 'zipfile' in setup.py.
Fix syntax error.
Put some comments into empty files do make them non-empty.
Cleanup: pep8ifying sources.

This changes have been applied to all python files using
https://github.com/htgoebel/pep8ify and the result has been checked.
Remove '%' string formatting in logging everywhere.

This changes have been applied to all python files using fix
logging_mod_operator from https://github.com/htgoebel/pep8ify (branch
coherence-project) and the result has been checked.
Add install_requires to setup.py.
Fix she-bang line: call python via /usr/bin/env.