s4:provision - Some rework (continuation)

s4:provision - Some rework (continuation)

- Fix up "servicePrincipalNames" attributes on the DC object
- Add some informative comments (most in "provision_self_join.ldif")
- Add also comments where objects are missing which we may add later when we
  support the feature (mainly for FRS)
- Add "domain updates" objects also under "CN=Configuration" (they exist twice)
- Add the default services under "Services" to allow interoperability with some
  MS client tools
- Smaller changes