Follow new infra setup for translations, see spec
http://specs.openstack.org/openstack-infra/infra-specs/specs/translation_setup.html
for full details.
This basically renames oslo.db/locale/oslo.db.pot to
oslo_db/locale/oslo_db.pot.
For this we need to update setup.cfg.
Update also domain name in _i18n.py.
Change-Id: I5b3052f840201557f3b1c85effeda3bb3318a9ee
Move the public API out of oslo.db to oslo_db. Retain the ability to
import from the old namespace package for backwards compatibility for
this release cycle.
Blueprint: drop-namespace-packages
Change-Id: Ie96b482b9fbcb1d85203ad35bb65c1f43e912a44
Module `gettextutils` from common code was graduated to oslo.i18n, so it
would be great if we reuse this library.
Change-Id: Ie5836b82723fc80c1d54e5e65eac8565cf905c5a