volume driver versions are inconsistently implemented

[Walt Boring]

The different volume drivers seem to have a concept of a version in each of them, but they are all inconsistently implemented.
Some drivers create a VERSION in the module, others create something like <name>_VERSION, while others don't have a version.

It would be nice if every driver implemented the VERSION the same way and when a driver gets started it's name and version were printed out in the log file.

Only some of the drivers actually use that version when reporting the driver_version in the get_volume_stats() call.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/42236

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/42236
Committed: http://github.com/openstack/cinder/commit/abac1a6c1c55c673603d4943711c02a09ed4c34d
Submitter: Jenkins
Branch: master

commit abac1a6c1c55c673603d4943711c02a09ed4c34d
Author: Walter A. Boring IV <email address hidden>
Date: Thu Aug 15 15:54:30 2013 -0700

    refactor/unify driver version strings

    This patch updates each driver to provide
    the same mechanism for reporting the version
    of the driver. It also includes fixing the
    reported driver version at get_volume_stats()
    time to be the version set in the driver.

    When the manager starts the driver it now
    logs the driver's name and version in the log file.

    fixes Bug #1212878

    Change-Id: Icefd065f885ad417735490e6ac90e2b21557d2dc