IBM Storwize driver: Retype the volume with correct empty QoS

* Currently for Storwzie driver, if the new type does not have QoS
configurations, the old QoS configurations remain in the volume after
retyping it. It should be retyped into a volume with empty QoS for the
Storwize driver.
* Refactor three dicts into one for better maintainance of the QoS keys
for Storwize driver.

DocImpact

Change-Id: I2b2801a4ef72ef02c11392ed00b56f5263a8a7e4
Closes-Bug: #1368595
(cherry picked from commit 26de1b1d829849665dae921b8be739194b84515d)
Deprecate / obsolete NetApp volume extra specs

The NetApp Data ONTAP (Cluster-mode) NFS & iSCSI drivers for Juno support
the Cinder pools feature, but the drivers are reporting two qualified
extra specs that must be converted to unqualified extra specs in order to
be used by the Cinder scheduler's capability filter. Furthermore, there
are four extra specs that must be deprecated due to having the pools
feature.  Warnings will be logged during volume creation if any of the
obsolete or deprecated extra specs are seen in the volume type.

Change-Id: I4dbd667610e481356304a12b8dae84cff61aa9d9
Closes-bug: 1374630
(cherry picked from commit 4cb4be4122a44dc99d6f29f065cdd32ae86273ce)
Fix race condition in ISCSIConnector _disconnect_volume_multipath_iscsi

This is a similar issue as seen in
https://bugs.launchpad.net/cinder/+bug/1375382

The list of devices returned by driver.get_all_block_devices() in
_disconnect_volume_multipath_iscsi will potentially contain broken
symlinks as the SCSI devices have been deleted from calling
self._linuxscsi.remove_multipath_device(device_realpath) right before
_disconnect_volume_multipath_iscsi but the udev rule for the symlink
may not yet have completed.

Adding in a check to os.path.exists() will ensure that we will not
consider the broken symlinks as an “in use” device.

Change-Id: I79c9627e9b47127d3765fcec5b7e3bacef179630
Closes-Bug: #1375946
(cherry picked from commit 4541521de576297d9b7d4115b040ff54773d9d50)
ZFSSA iSCSI driver cannot add multple initiators to a group

All initiators defined in zfssa_initiator property would be
added to the group.
Also fixed some typos related to initiators error messages.

Change-Id: Iec6c90702e5aafa153b4a7f1e429974ac450afc0
Closes-Bug: #1369750
(cherry picked from commit f94d671e627dd7b5143422ffe739418fcfb51a70)
Merge "Deprecate / obsolete NetApp volume extra specs" into proposed/juno
Merge "Fix race condition in ISCSIConnector _disconnect_volume_multipath_iscsi" into proposed/juno
Merge "ZFSSA iSCSI driver cannot add multple initiators to a group" into proposed/juno
Merge "IBM Storwize driver: Retype the volume with correct empty QoS" into proposed/juno