Backup Metadata Import is broken

[Gorka Eguileor]

Currently backup metadata import is not working properly, as it doesn't import all fields from provided import data.

This results in many issues, depending on the backend, they could range from not being able to use any backups at all, to not being able to reconstruct incremental backups.

This affects all backup drivers.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/183222

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/200927
Committed: https://git.openstack.org/cgit/openstack/cinder/commit/?id=e1ec05dc0da3b53337b1ca6d80d79741dc62c640
Submitter: Jenkins
Branch: master

commit e1ec05dc0da3b53337b1ca6d80d79741dc62c640
Author: Gorka Eguileor <email address hidden>
Date: Sat Jul 11 13:57:41 2015 +0200

    Move import and export backup metadata to object

    Encoding and decoding of backup metadata was being done in the backup
    driver, but since this is not driver specific data we are talking about
    it makes more sense to have this logic in the backup object.

    This patch moves the logic to the object while still allowing to have
    importing/exporting driver specific backup data, even when this is not
    being used at the moment.

    Related-Bug: #1455043
    Related-Bug: #1476416
    Change-Id: I690748e4542880d5e926f3cbf8cedfc86de5cb1f

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/183222
Committed: https://git.openstack.org/cgit/openstack/cinder/commit/?id=dbdb4cda00c01ed2ae5181e78559777216e0aa5f
Submitter: Jenkins
Branch: master

commit dbdb4cda00c01ed2ae5181e78559777216e0aa5f
Author: Gorka Eguileor <email address hidden>
Date: Sun Jul 12 13:30:03 2015 +0200

    Fix backup metadata import missing fields

    When importing backup metadata only required fields were being imported,
    and all other fields were being ignored.

    This led to some serious problems when importing backups back, since
    you would lose not only the original Volume ID, but also relevant parent
    id information needed to restore incremental backups.

    This patch fixes this by importing everything back and creating backup
    records with the right ID.

    Closes-Bug: #1455043
    Closes-Bug: #1476416
    Depends-On: Id7ab6e174c1fe85772477f03059c4f457c5c8b17
    Change-Id: Ia42ba73e9078d993c63f8e16308151ad11721ea9