Also make sure config_add_internal errmsg is returned to slapadd

Rename slapd/config.h to slap-config.h and update accordingly
Rename lloadd/config.h to lload-config.h and update accordingly

Reallocates sockets from old to new listener threads

Add LDAP_OPT_X_SASL_CBINDING option to define the binding type to use,
defaults to "none".

Add "tls-endpoint" binding type implementing "tls-server-end-point" from
RCF 5929, which is compatible with Windows.

Fix "tls-unique" to include the prefix in the bindings as per RFC 5056.

- give authid-rewrite's argument a name
- tidy saslauthz.c whitespace (mixed spaces/tabs)
- always declare slap_sasl_regexp_destroy: fixes an implicit declaration
  warning when configured without librewrite
- delete dead code: ENABLE_REWRITE implies SLAP_AUTH_REWRITE, so this
  code is never compiled
- make slap_sasl_regexp_rewrite_config static
- omit sasl_regexp unused fields when built with librewrite

This commits deletes all references and code for back-bdb and back-hdb.
There is some follow up work still necessary to flush out the admin
guide for back-mdb.

Leave olcTLSCertificateKey as its own attr, not a subtype

We're using PKCS#8 syntax, drop the OpenLDAP syntax OID.
Rename attribute accordingly.
Tweak validator to accept encrypted keys.

Fix incorrect matching rules for olcTLSCertificateKey and olcDbCryptKey
Fix SYNTAX for olcRootPW to be octetString

Add matching rules for all cases where it was missing.  Cleanup
incorrect types for a few attributes as well.  Fix network-timeout
handling in back-ldap/meta/asyncmeta.