Update notes for submitted changes

* Allow snapshot_delete for NFS/GlusterFS drivers
Update notes for submitted changes

* Fix typo in persona valid values
Update notes for submitted changes

* Use self.configuration to support the multi-backend case
Update notes for submitted changes

* Fixes dettach volumes in Windows cinder plugin
Update notes for submitted changes

* Switch all uses of 422 response code to 400.
Update notes for submitted changes

* Implement get_volume_stats in NFS driver
Update notes for submitted changes

* Pull Oslo log fix to enable root logger initialization