provision: simplfy by removing old code to manually create baseDNs.

provision: simplfy by removing old code to manually create baseDNs.

Previously, we would create the first record in the DB as an LDIF
file, with the expectation that the administrator would use slapadd to
create the database.

We now do everything over LDAP, which is far simpler, and allows the
LDB module chain to do its work, without special cases.

Also fix naming of the output schema when suggesting the comamnd line
to run ad2oLschema in provision-backend.

Andrew Bartlett
(This used to be commit e77375758d66e94e5e0b6e61a97c9281c3d9c71f)