Brian Warner dd84abd9f2 setup.py: work with tox under py3
This allows a python3-based "tox" (as shipped with modern debian and
ubuntu systems) to run setup.py egg_info, update_version, and sdist
commands. It moves the main "tahoe requires py2" check out of setup.py
and into allmydata.scripts.runner.run, where it gets applied at runtime
rather than build time.

It also changes the execfile(_auto_deps.py) and Versioneer-like "ask git
what our version string should be" code to work under both py2 and py3.

fixes ticket:2747
2016-03-22 22:34:42 -07:00
..