As discussed on the mailing list and described here:
http://wiki.openstack.org/CommonConfigModule
The module implements an API for defining configuration options and
reading values for those options that a user may have set in a config
file or on the command line.
The module will be part of openstack-common and glance will consume
it from there once openstack-common makes a release with an API
compatibility commitment.
Change-Id: Ib604c3de75d9066cd913c2de3007024b1f5ec9f8
32ca659630