Should resolve ITS#2664.

fall into the regular send_ldap_* functionality instead of calling into
those functions explicitly. Nested callbacks still aren't handled as
cleanly as they might be.

1. Glueing patch for proxy cache
2. test script update to avoid schema checking voilations (attributes set)
3. configuration patch for proxy cache

No longer accept initial and trailing spaces in these syntaxes.

negative error codes.

Plugins should never return positive error codes except in the case
of bind pre-operation plugins, where they should return SLAPI_BIND_XXX.

This should fix ITS #2616 ...

- chk_lanman did not free result from hash_lanman
- copied code to generate hash from hash_lanman to chk_lanman,
  this skips prepending "{LANMAN}"
- downcase stored password hash to ensure hex characters [a-f]
  have the same case

Currently discovered via a "feature", but should use a control.
Start of a control made, but needs to be better integrated (with
auto use in ldapmodify(1)).

(please review)

(preliminary modify/incr client-side code)

Fix logging messages (thanks Kent)

draft-ietf-ldapext-ldap-c-api-05.txt, and keep the old name as an alias.

- SyncRepl support in back-ldbm
- back-ldbm functions return LDAP return codes for internal operations (callback)
- subentry code copy from back-bdb
- Misc udpates