[Distutils] Multiple pips to go along with my multiple Pythons

[Skip Montanaro]

I try to maintain several built and installed versions of Python,
currently 2.6, 2.7, 3.2, 3.3, 3.4 and 3.5alpha, all built from the
tips of their respective branches in Mercurial.

What's the correct/best way to keep pip up-to-date for all those
versions? 2.7, 3.4 and 3.5 have ensurepip, but I think that just makes
sure you have pip, not that there is a version associated with a
specific version of Python, right? Do I just download the latest
tarball and run "PY setup.py install" for each version of PY?

Thx,

Skip