Windows: afslogon expand short domain names

Windows: afslogon expand short domain names

Depending on how the user specifies the domain name during login,
NPLogonNotify may be given a short or a full domain or kerberos
realm name.  If the name is the short name, attempt to expand it
automatically if there is no 'realm' configured for the short
domain name.

This patchset relies upon data in the local registry instead of
using an API such as NameTranslate in order to avoid network
queries to the domain controller that might not be reachable.

Change-Id: Ib2cd08bca5223fa847a462520074bb758191539d
Reviewed-on: http://gerrit.openafs.org/7650
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Jeffrey Altman <jaltman@your-file-system.com>
Tested-by: Jeffrey Altman <jaltman@your-file-system.com>