The new e_private field can be used for any backend purpose.  In LDBM,
it's used to point th the private entry info struct.  The LDBM entry
info struct is only visible to the LDBM cache.
WARNING: This change has not be ported to other backends!  Breakage is likely.

if strdup fails.  This is better than not checking, but we should
add orderly shutdown.

Most function and variable definitions are now preceded by its extern
definition, for error checking.  Retyped a number of functions, usually
to return void.  Fixed a number of printf format errors.

API changes (in ldap/include):
  Added avl_dup_ok, avl_prefixapply, removed ber_fatten (probably typo
  for ber_flatten), retyped ldap_sort_strcasecmp, grew lutil.h.

A number of `extern' declarations are left (some added by protoize), to
be cleaned away later.  Mostly strdup(), strcasecmp(), mktemp(), optind,
optarg, errno.