database configuration is not fully recorded in plugin configuration files

[yong sheng gong]

after https://review.openstack.org/#/c/27265/ is merged, the database configuration items are not fully recorded in various plugin's configuration files.

In addition, we reset the default value of some items in config.py:
db_session.set_defaults(sql_connection=_SQL_CONNECTION_DEFAULT,
                        sqlite_db='', max_pool_size=10,
                        max_overflow=20, pool_timeout=10)

the all configuration items are defined in https://review.openstack.org/#/c/27265/27/quantum/openstack/common/db/sqlalchemy/session.py

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/34515

[yong sheng gong (gongysh)]

sqlite related sqlite_db and sqlite_synchronous are defined
in 'default' section, which I think is a defect. And it seems
quantum does not use sqlite_db item.

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/34515
Committed: http://github.com/openstack/quantum/commit/74419faacf93a5e22ff6bd3f033a7fbd1c99a223
Submitter: Jenkins
Branch: master

commit 74419faacf93a5e22ff6bd3f033a7fbd1c99a223
Author: Yong Sheng Gong <email address hidden>
Date: Wed Jun 26 16:46:39 2013 +0800

    move database config items into quantum.conf

    Bug #1194784

    This patch syncs all the DB configuration items into
    quantum.conf and removes the related items of plugins' config
    file to avoid duplication.

    sqlite related sqlite_db and sqlite_synchronous are defined
    in 'default' section, which I think is a defect. And it seems
    quantum does not use sqlite_db item.

    Change-Id: Ia47102ced0e4169f45f10b85311f298d8c026d31