Create a branch for FahControl python 2 and master gets python 3

[informatorius]

Create a branch for FahControl python 2 so bug fixes can be made there. And let master branch get python 3 so the transition from python 2 can be made there.

[bb30994]

Good idea. The Long Term Support distros still contain python 2 for as long as anybody is still running them.

[roelfrenkema]

Ubuntu 20.04 no longer supports python-gtk2