PaganinIterator now also iterates through beta.

Next up is probably a way to define if we should iterate through delta,
beta or both....
Changed indentation, clarified some output messages
Now iterating through delta and/or beta

The PaganinIterator now only iterates through delta and beta if the user
wants to, otherwise only through delta.
To make that happen I am constructing a list of Deltas and Betas to
iterate through, thus changing some Delta to Delta[i] and Beta to
Beta[k] all over the script.
Also now fully `pep8` compliant according to Geany.