pypa/pip — pull request #1750 by dstufft (2014-04-24 12:01:15+00:00)
Title: Upgrade pip._vendor.distlib to 0.1.8

This major usefulness of this is:

* Allowed versions with a single numeric component and a local version component.
* Adjusted pre-release computation for legacy versions to be the same as the logic in the setuptools documentation.

Fixes #1555
Fixes #1639