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.

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

LBER_ALIGNED_BUFFER(OPERATION_BUFFER_SIZE), as discussed in ITS#4078.
Add a corresponding SyncOperationBuffer in overlays/syncprov.c.

easier to move into overlay private data

be preparing to use timestamps with sub-second resolution, really.)

define OPERATION_BUFFER_SIZE for dummy Operations