PSCSIStorageObject EVPD unit serial emulation
PSCSIStorageObject EVPD unit serial emulation

* Despite the fact that the underlying device might have a valid unit_serial,
  EVPD Unit Serial Number emulation works if there is no active EVPD
  information in INQUIRY Response payloads.
* Added a wwn argument to PSCSIStorageObject constructor, that works the same
  as for other backstores
* Only attempt to generate a random WWN or use a user-provided one if the pSCSI
  driver did not pick one up already from the LLD

roidayan/rtslib,Datera/rtslib,roidayan/rtslib,Datera/rtslib