Change rootpw, rootdn and suffix using ldap tools

Migration to the new OpenLDAP way of handling things keeps going.

At the moment, on EL, even if you set `$rootpw` in your manifest definition, it wouldn't be taken in account. You would have to set it manually into `/etc/openldap/slapd.d/cn=config/olcDatabase={2}bdb.ldif`
This happens because the `$rootpw` is correctly set in the `slapd.conf` file, but the new version of OpenLDAP does not look at it but at the `olcDatabase={2}bdb` DIT itself.

This commits, as the previous one uses `ldapmodify -Y EXTERNAL -H ldapi:///` to update the current `olcDatabase={2}bdb` DIT.

**Note :** ssl/tls configurations, DBDirectory and other item will come in a later commit. I though those ones are the most important at the moment.