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.

common controls across all tools.

            ================
Written by Hallvard B. Furuseth and placed into the public domain.
This software is not subject to any license of the University of Oslo.
            ================
Adapted by Kurt Zeilenga for inclusion in OpenLDAP.  My comments are
marked with enclosed with square brackets (e.g. [Kurt's comment] below.
            ================

If I run ldapmodify & co from a script, I don't want to use '-W password'
because the password shows up in the output of 'ps' for everyone,
and I can't pipe the password to 'ldapmodify -w' because -w uses
getpassphrase() which reads from the tty instead of stdin.
So I added '-y file' which reads the password from file.  The programs
exit if the file cannot be read.

[Complete contents of file is used as password.  Use:
	echo -n "secret" > password
to create a file with "secret" as the password.  The -n avoids
adding a newline (which would invalidate the password).  Note
that echo is a builtin and hence its arguments are not visible
to 'ps'.]

I changed ldapmodify, ldapmodrdn, ldapdelete, ldapsearch, ldapcompare.
I did not bother to change ldappasswd and ldapwhoami, because they
prompt for many passwords.  [I fixed up ldapwhoami.]

Rerun autoconf after applying this patch. [Done.]

Note:  I do not know if Windows NT has fstat(), so I set HAVE_FSTAT to
undef in portable.nt.  (fstat() is used to warn if the file is publicly
readable or writeable.)  [I used fstat() to set the buffer size to
read.]

[Note: using the contents of a file extends the tools to support
passwords which could not normally be provided using getpassphrase()
or via the command line.]

Hallvard B. Furuseth <h.b.furuseth@usit.uio.no>, Aug 2002.
[Kurt D. Zeilenga <kurt@openldap.org>, Aug 2002.]

Patch suggested by Matthew Backes <lucca@csun.edu>