Replaced with bi_entry_get_rw.
Implemented for back-bdb, back-ldbm, back-ldap.

and the lock goes away after txn_commit. Not sure what to do about the
cache if txn_commit actually fails though. Since txn_prepare succeeded,
should never happen. ???

needs to be integrated into the MSVC build system.

fix this if ACLs are expected to work on the local slapd.

no normalizer, a_nvals = a_vals.

Fix up for SLAP_NVALUES_ON_DISK

Make SLAP_NVALUES the default.