(PUP-3127) LDAP - introduce LDAP-Certificat Directory

Add ldapcrtdir settings to enable ssl based ldap connections on Solaris based Puppet-Master.
Without this implementation it is not possible to create ssl encrypted ldap connections on a Solaris system.
If the 'ldapcrtdir' parameter is not set or set to false (=> default), the connection is etablished as before.
Summarizing the rest of the ticket, on Solaris 11 or greater we could query ldapclient if `ldapcrtdir` isn't set. This uses smf under the hood. I'm going to follow up with whether we can use the ruby-ldap module to get that information.