(ITS#4665) slapo-ppolicy is leaking

[ando@sys-net.it]

Full_Name: Pierangelo Masarati
Version: HEAD/re23
OS: irrelevant
URL: ftp://ftp.openldap.org/incoming/
Submission from: (NULL) (87.28.220.33)
Submitted by: ando


slapo-ppolicy seems to leak in many circumstances, subtle or not.

1) when creating the response control value
2) when adding the controls to the response (here, moreover, it would at least
ignore, and possibly leak, any existing controls array)
3) when pre-pending the old password value during password change operations,
because the caller frees its original modifications list rather than the
contents of op->orm_modlist.
4) when parsing the history values

As a result, test022 itself was leaking some 25k on my 23bit machine.  This
should now be fixed in HEAD.

In fixing this, I've moved some allocation on the per-thread slab; it would be
great to move response control generation and so to that slab as well.