Implements HDS-Cinder HNAS Drivers

This change introduces HDS HNAS iSCSI and NFS Drivers.

HNAS NFS certification results:
  https://gist.github.com/sombrafam/6c73cb823ce75b0538bd

HNAS iSCSI certification results:
  https://gist.github.com/sombrafam/2625987243ec91d53c7a

Change-Id: I1a16f76887cf22dcf8ce0ed1dbc0b57327a87616
Implements: blueprint hds-hnas
Allow reset-state on attach and migration fields

The reset-state API call only sets that main status
column on the volume object.  There's also a method
to set attach status, however it turns out that due
to the implementation of the status validation method
in the parent class, this was impossible to use because
it only checked and accepted "status" NOT "attach_status".

This patch fixes that attach_status problem, it also implements
the ability to update the migration status.  A cinderclient change
will be needed to expose these calls as well.

DocImpact

Change-Id: I59e1bb2522f033c944fa07acf4876ca71c8c3d3f
Closes-Bug: #1308253
Merge "Implements HDS-Cinder HNAS Drivers"
Merge "Allow reset-state on attach and migration fields"