remove {} from procedures invocation, as noted in ITS#2641; copied annotations from postgres example

this module should not be used in production.

use ldap_find_control to find it. Added ldap_passwordpolicy_err2text().

(if only they were implemented :-)

and lots of cleanup (hence the commit)
(ldapmodify will need much more work for transactions)

Add ldap_find_control()

macros for transaction groupings