Allow publishing of URN:OID based attributes only

[surfnet-niels]

SR currently has a switch[1] to only publish URN:MACE:DIR based attribtes, which are rather obsolete, but hey. A similar feature is needed to allow only publishing URN:OID based attributes.

[1] "Do not add aliases of attributes"(default: Unchecked).
Eg: Unset/unchecked gives both urn:mace:dir:attribute-def:cn and urn:oid:2.5.4.3. Checked gives only urn:mace:dir:attribute-def:cn.