Description of Problem:

Addressbook does not allow filtering ldap search. Sometimes ldap directory
is not so well organized and it's impossible to limit search only to
persons by only setting proper base dn.

It would be usefull that one could set a search filter like: 

 Filter: (objectclass = organizationalPerson)

This way only persons would be returned. On baddly organized directory
search without filter returns usually accounts also.



Steps to reproduce the problem:
1. Contacts -> Tools -> Addressbook sources -> [Select server] Edit -> Advanced



Actual Results:

 Address search may return unwanted type of data


Expected Results:


 Search should return only wanted type of data (objectclass=something)


How often does this happen? 

 Always.


Additional Information:

 See Mozilla/Netscape (atleast v6.x) for reference implementation.