We add the flake8 configuration used so we ensure everyone uses the same.
We remove the usage of __all__ for non public API.
When possible, we rationalize the class name according to its __name__ and module.
issue9082
review297061002
* Allow callable in copy default
* Support dotted notation in copy default
* Use setdefault in copy
* Copy default when needed
* Do not set default state in copy
* Use callable and dotted notation in copy default
issue5576
issue7648
review72291002
Sergi Almacellas Abellana