Misc control cleanups (client only)

- implement pagedResults abandon by setting size=0
- misc code cleanup

LDAP Control Extension for Simple Paged Results Manipulation

contributed by Lynn Moss <lynnmoss@us.ibm.com> (ITS#2189)

applied with changes.

Written by Hallvard B. Furuseth and placed into the public domain.
This software is not subject to any license of the University of Oslo.

'ldapmodify -c' returned the error status from the _last_ LDIF entry,
so a bad entry followed by a good entry returns success.
This patch makes it return the status of the last _failed_ entry,
or 0 if all entries succeeded.

#if'd out by default, but it works fine. Kept both for easy comparison.

Make sure client controls are not specified multiple times.
NT port updates.

Update NT build.