Use ldapssl_init() for ldaps support instead of trying

Use ldapssl_init() for ldaps support instead of trying
to do it manually with ldap_init() + ldapssl_install_routines().
Use tls_cert and tls_key for cert7.db and key3.db respectively.
Don't print debugging info for options that are not set.
Add warning if start_tls specified when not supported.