Add automatic creation and deletion of Purity hosts for PureISCSIDriver

The driver will now be responsible to manage hosts for new initiators
which do not already have a host created for them. This will allow for
backwards compatibility with the previous version that relied on hosts
being pre-configured for use by Cinder.


Implements: blueprint pure-iscsi-automatic-host-creation
Change-Id: I04b554e1a21128d55eddc21afda7108a868e4248
Add volume attribute support to volume created using clone, snapshot

The following patch adds support for volume attributes (setting of
storage pool, replicas, dio, write affinity etc) in case of volume
creation triggered using snapshot, clone.

Change-Id: Ia6e24cafb85c0b2996e2524b45c189fb38e83848
Closes-Bug: #1386650
Merge "Add volume attribute support to volume created using clone, snapshot"
Merge "Add automatic creation and deletion of Purity hosts for PureISCSIDriver"