Cleanup i18n marker functions to match Oslo usage
Cleanup i18n marker functions to match Oslo usage

Define marker functions as per usage in documentation.
http://docs.openstack.org/developer/oslo.i18n/usage.html

Change-Id: Id3986c2119eaf5af72d0c2bce548083a3553abf5

stevelle/glance,openstack/glance,openstack/glance,rajalokan/glance,rajalokan/glance,stevelle/glance,openstack/glance