re-implement python setup.py publish with twine

[chfw]

current implementation is deprecated

[jayvdb]

It is unclear how setuptools sub-commands will be handled in the future, especially the internal ones. e.g. pypa/setuptools#1684

Anyways, I suggest that we try to move towards external projects which provide distutils.commands entry-points, e.g. https://github.com/search?q=setuptools+command and https://github.com/search?q=distutil+command&type=Repositories

A specific example at https://github.com/WoLpH/sphinx-pypi-upload/blob/master/setup.py#L33

If setuptools tries to break its entry-points hook system, we could always re-implement it with some custom code injected into setup.py.

[jayvdb]

https://github.com/LEW21/pysetup-yaml2json shows how to get custom commands also working with distutils2 ; we can activate them with a setup.cfg template

[chfw]

distutils' example in sphinx looks neat. D2's example, showing python 3.3's pysetup, is neat too but seems new to the rest of us.

my doubt is, because I have no prior knowledge, if moban uses custom command as sphinx example, when our user do pip install moban, the custom command in moban is not available yet. Will pip try to read moban package after download and before installation?