1. Add the version module from openstack.common.
2. Create a ceilometer/version.py to set up the
version info.
3. Update setup.py from openstack.common.
4. Update documentation build to use the version module
directly instead of running setup.py to get the version.
5. Update setup.py to use the new version module.
Change-Id: I9d8be62b8ece75090bf335d27adb59a46e3d6263
Signed-off-by: Doug Hellmann <doug.hellmann@dreamhost.com>