Windows: RXAFS_BulkStat failures

The RXAFS_BulkStat RPC is quite brain dead. The client requests
status information on up to AFSCBMAX FIDs.  The file server replies
success only if all of the client credentials provide access to
all of the requested FIDs.  If status info cannot be provided
for any one of the FIDs, the error code of the failure is returned
with no context as to which FID failed.

To simplify the logic within the cache manager a new local error
code, CM_ERROR_BULKSTAT_FAILURE is introduced to replace whatever
error was received from the file server.  This error is returned
by cm_TryBulkStat and cm_TryBulkStatRPC.  The caller of either of
those functions should interpret the error to mean that the current
user context cannot be used to perform a bulkstat operation against
the provided cm_scache directory.  Instead, individual RXAFS_FetchStatus
operations must be performed.

This patchset implements such error handling for both the SMB and
RDR interfaces.  This change permits the Windows cache manager to
properly enumerate a directory for which the user only has list
permission and cannot read the status info for files and symlinks.

Reviewed-on: http://gerrit.openafs.org/9080
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Jeffrey Altman <jaltman@your-file-system.com>
Tested-by: Jeffrey Altman <jaltman@your-file-system.com>
(cherry picked from commit cb414f6899212f314313a781b63486661e9d1394)

Change-Id: Icec0dc311c6c9152d15d7e61c32a001e651d95ca
Reviewed-on: http://gerrit.openafs.org/9115
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Jeffrey Altman <jaltman@your-file-system.com>
Windows: Unique file ID is per volume

The unique file ID returned as part of the BY_HANDLE_FILE_INFORMATION
data structure obtained via GetFileInformationByHandle() is only
guarranteed to be unique within the volume where volume uniqueness is
determined by the volume's serial number.

It therefore doesn't make sense to return the volume id as part of
FILE_INTERNAL_INFORMATION IndexNumber.  Instead return Vnode and
Unique as that is what ensures uniqueness within an existing AFS
volume.

Unfortunately, {VolId, Vnode, Unique} does not guarantee uniqueness
for when multiple cells are in use.

Reviewed-on: http://gerrit.openafs.org/9108
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Jeffrey Altman <jaltman@your-file-system.com>
Tested-by: Jeffrey Altman <jaltman@your-file-system.com>
(cherry picked from commit 9b48daff341773580b3635e476fea112374986f2)

Change-Id: Iae521bed6874595c061b1ecc530e9f1d7597fc34
Reviewed-on: http://gerrit.openafs.org/9116
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Jeffrey Altman <jaltman@your-file-system.com>