pass ConfigReply to overlays; don't complain unless once-only overlays are instantiated multiple times

pass ConfigReply to overlays; don't complain unless once-only overlays are instantiated multiple times

Fix paged results control handling

Unifdef SLAP_LIGHTWEIGHT_DISPATCHER
Use thread-specific data in pool_context()
Added native thread-specific data support
Concurrency tweaks:
  store conn->c_sd, don't use ber_sockbuf_ctrl to retrieve it.
  use per-thread free lists for operations, no mutexes needed.

re-parse in the backend. Keep track of pagedresult controls and state
in backglue.

  store conn->c_sd, don't use ber_sockbuf_ctrl to retrieve it.
  use per-thread free lists for operations, no mutexes needed.

ITS#5072
ITS#5168