Remove deprecation warning when loading stores

[Flavio Percoco]

Tracking the need of removing deprecation warning and the _EXTRA_STORES global from stores/__init__

[Flavio Percoco (flaper87)]

this is to be done for Juno-2

[Erno Kuvaja (jokke)]

Has there been progress on this bug?

[Flavio Percoco (flaper87)]

I'm taking it, I'll fix it as part of the glance.store switch-over

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/100636
Committed: https://git.openstack.org/cgit/openstack/glance/commit/?id=f6e7992a68f6ab36f87604fffbe5349f2a12b25e
Submitter: Jenkins
Branch: master

commit f6e7992a68f6ab36f87604fffbe5349f2a12b25e
Author: Flavio Percoco <email address hidden>
Date: Tue Jun 17 16:04:15 2014 +0200

    Adopt glance.store library in Glance

    This commits removes the old `store` package from glance and adopts the
    usage of the new glance.store library. The library was designed to
    preserve backwards compatibility as much as possible. In fact, most of
    the changes in this patch are related to function args ordering and not
    function renames or workflow changes.

    Some changes that are worth mentioning:

    1. Glance store doesn't rely on a global config object. All config
    options must be explicitly registered.

    2. All store operations now accepted an optional context. This is a
    fallout from the context not being required in the `Store` constructor
    anymore.

    3. Store drivers are behind a private package called `_drivers` and
    they're not suppose to be accessed directly. Instead, functions like
    `get_store_from_scheme` should be used.

    4. Stores are disabled by default

    5. All the store specific options are under the `glance_store` group.

    DocImpact:
    The old store related configuration options have been moved under the
    `glance_store` section. However, the old options will go through a
    deprecation path. That is, they'll still be read from the `DEFAULT`
    section to give deployers enough time to update their config files.

    In k-2, the deprecated options will be completely obsolete.

    Closes-bug: #1291848
    Implements-blueprint: create-store-package

    Change-Id: Iaacc70993ad5da292b93de42bbecda73d53b19fd