Converts method headers to Python docstring format in AffineCipher.

As promised, here's the docstring conversion I mentioned... idk, probably at the beginning of the semester.

Here's the Google Python Style Guide as a reference; I've used both their Python and BASH style guides to great effect:

http://google-styleguide.googlecode.com/svn/trunk/pyguide.html#Comments

The official docstring spec can be found here:

http://www.python.org/dev/peps/pep-0257/

And finally here's a really brief walkthrough of using docstrings in Python interpreter:

http://epydoc.sourceforge.net/docstrings.html

Let me know if I can help with anything else!
:FF: