Windows: preserve prior vlserver list on dns failure

Do not destroy the existing vlserver list if the DNS resolver query
fails.  Continue using the prior vlserver values until a DNS response
is obtained.  This will result in repeated DNS queries and a delay
if there is continued failure, but it will permit VL RPCs to continue
to be issued in the face of a DNS failure or misconfiguration.

Reviewed-on: http://gerrit.openafs.org/11457
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Jeffrey Altman <jaltman@your-file-system.com>
(cherry picked from commit 5ebe2437efa7a64f0b0cc61e2123f9ae766b84cf)

Change-Id: If2194871e97eb213ce2fc5da12aa7c759492564d
Reviewed-on: http://gerrit.openafs.org/11499
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Jeffrey Altman <jaltman@your-file-system.com>
Windows: !overwrite IOMgr populated FileInfo data

I/O Manager will populate the FILE_ACCESS_INFORMATION,
FILE_MODE_INFORMATION, and FILE_ALIGNMENT_INFORMATION portions of
a FILE_ALL_INFORMATION structure prior to forwarding a FileAllInformation
FileInfo query to the file system.  There is no need for the file system
to duplicate the effort.

Reviewed-on: http://gerrit.openafs.org/11478
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 06995ceb4d664c3f14f6626da447cf9891470719)

Change-Id: Icf21e76f564a3df8c3808a36834f04b92dc30c46
Reviewed-on: http://gerrit.openafs.org/11500
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Jeffrey Altman <jaltman@your-file-system.com>