[Distutils] PEP440 and fork versioning

I'm wondering if PEP440 should recommend how to version forks? It's fairly common to fork dependencies temporarily until the change can be released upstream. Ideally, you want to version a fork (and keep the same name) so that it fulfills the requirement, but be obvious that it's a fork. Although pip allows overriding requirement consistency, consistency is preferred, and needed in cases where a `pkg_resources.require` enforces it in a console script. As it is now, the "post-release" scheme works for this, but it's not the intended use case. Marcus