LDAP support

[Ralph Seichter]

* Lars Täuber:

> Yes, thanks. This is what we need.

Until I find time to upgrade the documentation, the following SQL
statement might help to illustrate the configuration.

  INSERT INTO ldapserver (id, name, port, use_ssl, search_base,
    search_filter, attr_uid, attr_cn, bind_password, bind_user)
  VALUES (
    100,
    'ldap.example.com', 636, 1,
    'ou=mailusers,dc=example,dc=com',
    '(mail={0})', 'uid', 'cn',
    'PASSWORD', 'cn=automx2,ou=services,dc=example,dc=com'
  );

An encrypted connection (LDAPS) is used and the filter and attributes
work with objectClass=inetOrgPerson.

Now all that is required is to set domain.ldapserver_id for the domains
one wants to tie to the above server. I hope this helps.

-Ralph