fix different issues with referrals in searches; remove unused tests; cleanup referrals in tests so that they don't get chased; improve schema checking in modrdn and updates in general; minor cleanup

various issues related to working with schemacheck off; allow referrals to be created as separate objectClasses, so they work with schemacheck on (may rework them to be treated as normal data)

fix several schema checking issues; add rename specific statement for entry renaming without losing ID (helps e.g. in renaming referrals, otherwise referential integrity would prevent del/add because of referenced stuff in ldap_referrals and ldap_entry_objclasses); referrals need schemacheck off otherwise objectClass chain is invalid (they need to be attached to another objectClass by now; will address this later)

fixes for ITS#3480,3485,3489; implementation of DISCLOSE access for all operations (ITS#3472); ITS#3432.4; added value validate/pretty when applicable (see comments and #defines in back-sql.h)

database, and it will only perform writes it received from the provider,
so referring back to the provider is pointless. (And of course, the
consumer never chases referrals.)

use tmpmemctx for bsi_attrs (should be used more for temporaries)
fix ITS#3480: allow to fetch all attrs or provide hints
fixed access check to entry for rename
TODO: fetch entries for access checking in selected code portions (e.g. rename)

Add dependencies