Releasing Oslo's setuptools helper APIs as an oslo-build package

The openstack.common.{setup,version} modules in oslo-incubator are in use by most projects in OpenStack.

We should be getting close to being able to release it as a standalone library. Monty did a prototype of this called "pbr".

This blueprint is about extracting some of the ideas from PBR, applying them to the code in oslo-incubator and eventually releasing oslo-build.

This blueprint is about taking pbr releasing it as an Oslo library package.

Discussion here: http://lists.openstack.org/pipermail/openstack-dev/2012-November/003342.html