Windows: add RDR_ExtAttributes

Windows: add RDR_ExtAttributes

Add RDR_ExtAttributes to compute the file attributes for redirector
queries.   The attributes reported via the RDR interface need to be
different from the SMB interface because the SMB interface does not
support reparse points nor does it support DFSLinks.

Change-Id: I5d5172f5afc1d50e2622e2068e20447cd1098fbb
Reviewed-on: http://gerrit.openafs.org/9611
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Jeffrey Altman <jaltman@your-file-system.com>
Tested-by: Jeffrey Altman <jaltman@your-file-system.com>