Object copy XML LastModified tag inconsistent with S3

[Darryl Tam]

When performing a successful object copy, the LastModified tag in the XML response contains the last modified timestamp of the source object instead of the last modified timestamp of the newly copied object. S3 also appears to add ".000Z" to the end of each LastModified timestamp.

Sample S3 response:

<CopyObjectResult xmlns="http://s3.amazonaws.com/doc/2006-03-01/"><LastModified>2015-09-15T23:22:12.000Z</LastModified><ETag>&quot;60b725f10c9536c70d912365dfe8191b3&quot;</ETag></CopyObjectResult>

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/223880

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/223880
Committed: https://git.openstack.org/cgit/openstack/swift3/commit/?id=d7bbb730bd7b14f136134c3585992d5276401c98
Submitter: Jenkins
Branch: master

commit d7bbb730bd7b14f136134c3585992d5276401c98
Author: Darryl Tam <email address hidden>
Date: Tue Sep 15 17:10:34 2015 -0700

    Ensure object copy response timestamp tags consistent with S3

    The LastModified tag now properly reflects the timestamp of the newly
    copied object, rather than the original object.

    LastModified timestamps are now accurate to the millisecond to be
    consistent with S3 responses.

    Request.check_copy_source no longer returns timestamp as it's no longer
    necessary.

    Change-Id: Iffe70cb49701142a09c75b7cc33aaaea4e846144
    Closes-Bug: #1496170