SLAPI always assigning connection and operation IDs of zero for internal
operations, such operations would cause a stale contextCSN to be returned from
slap_get_commit_csn(). As a result, SLAPI internal updates would be invisible
to replicas until an external update was made. Also, SLAPI internal operations
never called slap_graduate_commit_csn() which leaked pending CSNs.

Also included in this patch is a general cleanup of some of the SLAPI code.

Note that we need to use a separate mutex on conn_nextid to avoid a deadlock
where a post-operation plugin tries to acquire connections_mutex, having locked
the per-connection mutex, while the listener thread tries to acquire the
per-connection mutex (having locked connections_mutex). connection.c needs to
be fixed to acquire mutexes in the same order.

works with IBM db2 as well; at this point the tsts are assumed to wok with any RDBMS that allows write operations

more definitive improvements; now write operations are consistent; plugged some more leaks/invalid frees; tests are more complete.  IBM db2 doesn't pass write test because the entries are written in a different order; need to write a script that sorts the results...

  and the objectClass right after caching, even if not requested,
  while subsequent searches are fine;
- the response callback needs be apended at the end of the
  callback list, otherwise the resulting entries are cached
  before other overlays can alter them
- the callback structure and its contents needs be freed

from within a rebind function.

is passed in.

attrs=*,+ becmoes the default behavior when attrs are not specified in syncrepl definition. When attrs are specified, operational attributes other than objectClass, structuralObjectClass, and entryCSN need to be explicitly specified to be included in the replication content.

test for back-sql; disbled by default, requires some preparation (essentially the RDBMS and the ODBC) before being run

allow to search for "auxiliary" objectClasses (i.e. those in ldap_entry_objclasses); allow to return all objectClasses including "auxiliary"; various cleanup

Set flag for hasSubordinates and subschemaSubentry. Strip dynamic attributes
before storing entries in syncrepl.