Windows: Obtain File Attribs for DFS Link target

The AFSRetrieveFileAttributes() function is used to acquire the
attributes for an AFS symlink.  The result is either returned directly
to the application or used internally to determine the attributes
to be exposed by reparse points.

If the evaluated symlink crosses a DFS Link the redirector cannot
return the request to IO Manager to evaluate the target.  Instead
the redirector must handle the request internally and attempt to
read the attributes of the target object.

Reviewed-on: http://gerrit.openafs.org/11399
Reviewed-by: Peter Scott <pscott@kerneldrivers.com>
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Jeffrey Altman <jaltman@your-file-system.com>
(cherry picked from commit d5b6a545ed1e9f01c295280495b806981d9877d3)

Change-Id: Ic5a6861dfb09f473ca679a6ce2a69c7a32f42a86
Reviewed-on: http://gerrit.openafs.org/11411
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Jeffrey Altman <jaltman@your-file-system.com>