first round of s/sprintf/snprintf/; the rationale is: truncate error messages rather than buffer overflow; otherwise, assert that no buffer overflow occurred.  In some cases, error handling could be added.

don't allow large search operations that touch more entries churn the
existing cached entries.

Fix filter normalization

ITS#5211 spec says we must ignore invalid cookies

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.

ITS#5072
ITS#5168

error message propagation fix