Implement a basic backup-volume-to-swift service

Implements: blueprint volume-backups

This patch adds the new service, api and basic unit tests

Change-Id: Ibe02c680c5e9201d208c92e796e86ad76b4b54b3
Fix stale volume list for NetApp 7-mode ISCSI driver

While contacting filer through DFM in order to create volume from
snapshot, the operation may fail with an error "No entry in LUN
table for volume". Although the LUN representing the volume was
created on the filer, the LUN list was not refreshed in time, which
 caused an error. This fix handles this situation for creating
volume from snapshots.

Note that this fix adds the requirement that the driver host and
DFM machine should be reasonably time-synchronized.

Fixes bug 1095633

Change-Id: I77fff4c36a3af72d28f2d01988a6067919093718
Skip timestamp check if 'capabilities' is none

fix bug: #1131011

Change-Id: I6266560627d03d95862a7f2c85ac63e2e9daef6b
Merge "Implement a basic backup-volume-to-swift service"
Merge "Fix stale volume list for NetApp 7-mode ISCSI driver"
Merge "Skip timestamp check if 'capabilities' is none"