Reset-state and snapshot-reset-state for multiple objects

This allows a user to call reset-state or snapshot-reset-state on a
list of objects.  The behavior is modeled after a similar change to
delete multiple volumes.

$ cinder reset-state good_volume good_volume_2
<no output>

Error behavior is as follows:

One success/one failure:
$ cinder reset-state good_volume asdf
Reset state for volume asdf failed: No volume with a name or ID of 'asdf' exists.

One failure:
$ cinder reset-state asdf
ERROR: Reset state for volume asdf failed: No volume with a name or ID of 'asdf' exists.

Two failures:
$ cinder reset-state asdf qwert
Reset state for volume asdf failed: No volume with a name or ID of 'asdf' exists.
Reset state for volume qwert failed: No volume with a name or ID of 'qwert' exists.
ERROR: Unable to reset the state for any of the specified volumes.

Related-Bug: 1241941
Closes-Bug: 1256069
Change-Id: Id0a36fb7de0d69be0dac98ea04e4708775250b7a
Fix broken argument name in v2 volume extend routine

The new_size attribute was misspelled, causing the volume extend
operation to fail with:

    ERROR: 'Namespace' object has no attribute 'new_size'

This happens only with the v2 API, v1 works fine.

Change-Id: Icb6b5008dad229f21e7906d9b5342d41f5e760cd
Closes-Bug: #1259552
Merge "Reset-state and snapshot-reset-state for multiple objects"
Merge "Fix broken argument name in v2 volume extend routine"