19.8.0-python3

This is the initial Python 3 version of the Broadband Platform. It has been tested and the results for all methods (except Irikura Recipe 2) are equivalent to results produced by the Python 2 based BBP v19.4. The Irikura Recipe 2 differences are due to changes in that method, and are not due to the change in Python versions. This Python 3 release is a minor release, without updated documentation.