MFC r269497:
Add support for Windows dialect of EXTENDED COPY command, aka Microsoft ODX.

This allows to avoid extra network traffic when copying files on NTFS iSCSI
disks within one storage host by drag'n'dropping them in Windows Explorer
of Windows 8/2012.  It should also accelerate Hyper-V VM operations, etc.
MFC r269587:
Reimplement WRITE USING TOKEN with Block Zero token using WRITE SAME.

On my ZVOL of SSDs that increases speed of zero writing in that way from
1 to 2.5GB/s by reducing CPU overhead.
MFC r269622:
Fix several issues and inconsistencies in UNMAP capabilities reporting.

This makes Windows 2012 to start using UNMAP on our disks.
MFC r269631:
Reduce reported additional INQUIRY data length.

sizeof(struct scsi_inquiry_data) of 256 bytes combined with off-by-one
error in the changed code gave total INQUIRY data length above 255 bytes,
that was maximal INQUIRY length in SPC-2.  While SPC-3 increased the
maximal length to 64K, at least sg3_utils are still confused by that.