r12984: add parse code and ldbsearch cmdline code for

r12984: add parse code and ldbsearch cmdline code for
NOTIFICATION LDAP Controls
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/ldap/ldap/ldap_server_notification_oid.asp

this doesn't work yet, but it shows that we need to extend ldb to correctly
handle async requests...

metze