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 after:	2 weeks
Sponsored by:	iXsystems, Inc.

(cherry picked from commit abcceae4d713d8abd2a93301c46a5475d6b256a6)