2.4.0 patches need review

HI!

I've committed a larger patch contributed by Rich Megginson fixing SF#2829057
[1] and adding generic support LDAPv3 extended operations. Many thanks to him.

I've done some tests for [1] by successfully using the LDAP persistent search
control against eDirectory and OpenDJ (OpenDS fork) and receive/decode the
response control. Also a case which does not seem to work with recent
python-ldap 2.3.13.

But I think this large patch needs much more review and some decision
regarding the arguments passed to and results returned by method
LDAPObject.result4().

So I'd like to encourage all the list readers to checkout CVS HEAD and play
with it.

Ciao, Michael.

[1]
http://sourceforge.net/tracker/?func=detail&aid=2829057&group_id=2072&atid=352072