- Tweak error code/message for absent directory, including database directory.
- Catch closedir() error.
- ldif_tool_entry_close(): Free entries and reset entry list.
- Propagate any error to slapcat & co.

- Parse sorted attrs more carefully:
  Accept only attr={num}val.ldif and attr=val{num}.ldif and only base 10.
  Sort "attr=foo" before "attr=foo{n}".  Truncate at ".ldif" while sorting.
- Make the sort order independent of the LDIF files' order in the directory.

r_enum_search() -> ldif_send_entry() + ldif_readdir() + ldif_search_entry().
enum_tree() -> search_tree().  fullpath() -> fullpath_alloc() + FILL_PATH().
No functionality change except catching malloc and opendir() errors.

- Do not modify op->ors_scope, pass scope parameter instead.
- Save copies of dn/ndn before sending with REP_ENTRY_MODIFIABLE.
- Only the search baseDN may produce noSuchObject.
- More accurate result code.

- Sending continuation references:
  Drop an unnecessary and wrong LDAP_SCOPE_BASE check.  The correct
  check would have been for DN == baseDN.
  Do not rewrite the scope, the caller already did.
- ldif_prepare_create(): Check that parent/newSuperior is not a referral.
- Rewrite ldif_back_rerferrals().  Better error handling.  Always pass
  refs through referral_rewrite().  As in back-bdb, apply manageDSAit
  only to the baseDN and do not use default_referral.

Add move_dir() macro, matching move_file().

- Move mkdir() into ldif_write_entry().  Modrdn lacked this.
- Factor tests for whether to create entry & dir out to ldif_prepare_create().
- Ensure an entry always exists if the corresponding subtree directory does.
- Move get_parent_path() up, accept NULL output param and malloc errors.

- Rename temporary filename patterns from "<rdn>.ldifXXXXX" to "<rdn>.XXXXX".
- Add and start using ldif2dir_len() & co.

- Start moving file handling near the top - move_file(), ldif_tempname().
- Rename get_entry_for_fd() -> ldif_read_entry() and move open() into it.
  Rewrite slurp_file() as ldif_read_file(). Just stat() if output param==NULL.
- Rewrite ldif_write_entry(). Add LDAP_DEBUG_TRACE output.

- Reset rs->sr_text on success in apply_modify_to_entry(), not in its callers.
- Fix error test from ldif_write_entry() in ldif_move_entry().
- Start changing LDAP_UNWILLING_TO_PERFORM -> LDAP_OTHER for internal errors.
- Pass around LDAP result codes instead of errno.
- Rename spew_entry() -> ldif_write_entry(), move entry2str_mutex lock into it.
- Some other preparation for upcoming changes.

eat all the substrings assertion if the attribute type does not support substrings matching (ITS#5803)

lookup entry id when equality on entryDN (proposed fix for ITS#5791; does not work for back-hdb, though)