already open.

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)