NETLOGON pipe improvements

NETLOGON pipe improvements

Patch for bug #4939

This refactors the NETLOGON code related to this bug:

- Introduces a new "SYNCSTATE" enum required by the "DatabaseSync2" call (acc.
to WSPP)
- Make "DatabaseSync" dependant from "DatabaseSync2" (acc. to WSPP)
- Let "DatabaseSync2" return NT_STATUS_NOT_IMPLEMENTED (I'm not sure if this is
also true when a domain is running in mixed mode)
- Make "LogonControl" and "LogonControl2" dependant form "LogonControl2Ex"
(acc. to WSPP)
- Let "LogonControl2Ex" return WERR_NOT_SUPPORTED for now