Windows: NPGetConnectionPerformance

Windows: NPGetConnectionPerformance

Restore the implementation of NPGetConnectionPerformance
in AFSRDFSProvider.dll.  This time just return 0 for all fields
except for the preferred read/write size which is set to 64K.

When this function is not implemented at all, a query for
performance of a \\AFS path will be processed by the SMB
redirector.  This can result in a 20 second timeout while waiting
for the SMB Browser query for "AFS <20>" to complete.

Change-Id: I67f7a3f0bb20a4be791bc153109e4e91144e00af
Reviewed-on: http://gerrit.openafs.org/7645
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Jeffrey Altman <jaltman@your-file-system.com>
Tested-by: Jeffrey Altman <jaltman@your-file-system.com>