Windows: Report Case Sensitive Search

Return the FILE_CASE_SENSITIVE_SEARCH volume flag as part of afs
volume properties.   NTFS does and our search algorithm is case
sensitive first, then case insensitive.

Change-Id: I64857cdf8712847064c8271956cebe2bdbe487df
Reviewed-on: http://gerrit.openafs.org/9850
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Jeffrey Altman <jaltman@your-file-system.com>