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>
Windows: netbios name comparisons are case insensitive

When parsing the symlink target string to categorize it as AFS Symlink
or DFS Link, the comparison with the netbios name string must be case
insensitive.  Otherwise, symlinks are reported to the redirector as
DFS Links.  For the most part they will work since the AFS redirector
requesting MUP to Reparse the \\AFS path will call back into the AFS
redirector.  However, the attributes on symlinks to files will be wrong
as DFS Links can only be links to directories.

Change-Id: Ia9652991549b0783f7a534b071ff99ceabdd3382
Reviewed-on: http://gerrit.openafs.org/9612
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Jeffrey Altman <jaltman@your-file-system.com>
Tested-by: Jeffrey Altman <jaltman@your-file-system.com>