Some manila migrations have SQL code while manila uses ORM

[Valeriy Ponomaryov]

Manila uses ORM sqlalchemy as abstraction between DB layer and python entities.

Some DB migrations are performed using sqlalchemy and some don't. It causes problems with support of DB backends that are not tested on periodic approach, such as PostreSQL.

We need to port our migrations that use direct SQL code to analog from ORM because SQL code for several backends can differ.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/168983

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/168983
Committed: https://git.openstack.org/cgit/openstack/manila/commit/?id=bf7fc87067f0eef50e30932b14a249f7632c0733
Submitter: Jenkins
Branch: master

commit bf7fc87067f0eef50e30932b14a249f7632c0733
Author: Valeriy Ponomaryov <email address hidden>
Date: Mon Mar 30 19:00:44 2015 +0300

    Replace SQL code for ORM analog in DB migration scripts

    Replace explicit usage of SQL code with appropriate analog of ORM.
    It allows to keep abstraction between DB and python clear without
    potential incompatibilities due to differencies in SQL dialects.

    Change-Id: Ied97264cafcec0bcebd4c3ddc7b29185825c56a6
    Closes-Bug: #1437278