Tichy coding style

Tichy follows the python codding style defined by Guido van Rossum in
PEP0008 : http://www.python.org/dev/peps/pep-0008/

There is a script in the 'tools' directory called 'pep.py' that can be
used to check the code for coding style errors.

Anybody contributing to tichy : please read the PEP and use the script
to check your code before committing.