Instead of 'inclusion' make a pypi package

My guess is that instead of the inclusion mechanism we should really focus on moving openstack-common to its own pypi project with versions and depend on these versions inside the other components after folsom. I'd be willing to help out in what that may entail (probably not that much additional work). It would be nice to have this for the following reasons:

1. Components can depend on a version of openstack-common while openstack-common then can follow its own release cycle (if desired).
2. Bug tracking becomes easier when you can easily just reference which version a component depends on instead of having to figure out which version that component 'copied' from.
3. Others that I can't think of :-P