ready for 1alpha release

Currently discovered via a "feature", but should use a control.
Start of a control made, but needs to be better integrated (with
auto use in ldapmodify(1)).

- SyncRepl support in back-ldbm
- back-ldbm functions return LDAP return codes for internal operations (callback)
- subentry code copy from back-bdb
- Misc udpates

Replaced with bi_entry_get_rw.
Implemented for back-bdb, back-ldbm, back-ldap.

Coverted LDAP_LOG macro to use subsystem ID int values instead of string values

form Mikhail Sahalaev <M.Sahalayev@pgr.salford.ac.uk>.
Further work needed:
	add testxxx-matchedvalues
	rework ldapsearch(1) portion of patch to generalize use of options
---
Copyright 2001, Mikhail Sahalaev, All rights reserved.
This software is not subject to any license of University Of
Salford.

Redistribution and use in source and binary forms are permitted
without restriction or fee of any kind as long as this notice
is preserved.

Added LDAP_LOG messages

added backend-side support for on-the-fly operational attributes; added hasSubordinates to schema and back-ldbm

slapadd core-dumps when destroying db's env (Sleepycat 3.2.9) (ITS#1239)
Only call ldbm_shutdown_env if the database has been opened, ie. when
li->li_dbenv != NULL.  Would appear any time a shutdown occurred and
not all LDBM databases were opened.

for LDBM backends called "dbsync", which takes minimum of one argument up
to 3 args which are sync frequency, # of delays, and delay periods.  See
man page update for "dbsync" configuration for more details.

backendsyncfreq <seconds>.  Setting this automatically enables
dbnosync (because the synchronizer takes care of it).

dbcachesize setting actually work for db-3.2.9.

the existing database "directory" directive) to allow setting
of a DB_ENV directory.  Should likely be database specific.