o start it as a service (gets around an annoying pause when starting u
p as a non-service).

should be done for all of LDBM.

subschema information.  subschema, monitor, config should be
per-backend subentries.

Misc other header changes.

r/w locks and thread pools.  Hide internal structures (using
pthread'ish technics).  Place common code in threads.c.  Move
no-thread code to thr_stub.c.  Move thread pool code to tpool.c.
Removed setconcurrency call from initializer, added 'concurrency'
directive to slapd.  Tested code under pthreads, pth, and no-threads.

other minor changes.

 ldap_pvt_thread_pool_backload() as needed.  All tests run OK on pthre
ads (linux), cthreads, NT threads, and Pth.