Manila does not have common approach for resource statuses

[Valeriy Ponomaryov]

We have several entities in Manila that do have statuses:

- Shares
- Snapshots
- Share Servers
- Share Access Rules

But Share servers use uppercase for it, all other lowercase. We should make all of them consistent.

Also, we should reuse them from one common place, for the moment Manila has a lot of in-place definitions instead of using common code.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/186520

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/186520
Committed: https://git.openstack.org/cgit/openstack/manila/commit/?id=0a7f44ad0769d95ab83f6ec6c4f2536354d2c2e5
Submitter: Jenkins
Branch: master

commit 0a7f44ad0769d95ab83f6ec6c4f2536354d2c2e5
Author: Valeriy Ponomaryov <email address hidden>
Date: Thu May 28 21:14:27 2015 +0300

    Transform share and share servers statuses to lowercase

    We have several entities in Manila that do have statuses:

    - Shares
    - Snapshots
    - Share Servers
    - Share Access Rules

    But some share and all share server statuses use uppercase for it.
    Make all of them consistent and transform them to lowercase.
    Add migrations for it.
    Also, remove two unused statuses and reuse all statuses from common place.

    Change-Id: I53e6a768c98977d3d94e761349b7446a9dfb4936
    Closes-Bug: #1459598