Fix OPENDJ-333: Missing entryUUID attributes in "cn=admin data" backend prevent updates from being replicated. Add EntryUUID values derived from DNs to admin-backend.ldif.

These changes use the new LDIF backend implementation so that the adminRoot backend is always present. The adminRoot LDIF backend is initially populated with the admin container entries, except for the cn=Servers container. To avoid breaking the setup and dsreplication tools, I have changed things so that the absence of the cn=Servers container entry implies that the server is not yet configured as an ADS server. I have commented out code that is no longer applicable.