(ITS#5412) Add operation should not require naming attrs

[h.b.furuseth@usit.uio.no]

Full_Name: Hallvard B Furuseth
Version: HEAD, RE23, RE24
OS: 
URL: 
Submission from: (NULL) (129.240.6.233)
Submitted by: hallvard


A somewhat belated ITS: ldapadd of
  dn: o=foo
  objectClass: organization
complains that "naming attribute 'o' is not present in entry".
RFC 2251 required this, but RFC 4511 changed it to the opposite:
The RDN attrs need not be present in AddRequest.attributes.

slapd and slapadd should generate them if they are missing.

I don't know if the change belongs in RE23.