Add LDAP upgrade over ldapi support.
    
    This disables all but the ldapi listener in DS so it will be quiet when
    we perform our upgrades. It is expected that any other clients that
    also use ldapi will be shut down by other already (krb5 and dns).
    
    Add ldapi as an option in ipaldap and add the beginning of pure offline
    support (e.g. direct editing of LDIF files).