part of windows fixes already committed.

Fix dec to bin for zero value
silence warnings

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#5127

ldif_read_record() doesn't distinguish errors from EOF, this is kind
of futile.

Extend ldap_create_control() to supporting creating such.