update are now fully supported and no longer require
defines to enable. We now no longer overload the
NSEC3PARAM flag field, nor the NSEC OPT bit at the
apex. Secure to insecure changes are controlled by
by the named.conf option 'secure-to-insecure'.
Warning: If you had previously enabled support by
adding defines at compile time to BIND 9.6 you should
ensure that all changes that are in progress have
completed prior to upgrading to BIND 9.7. BIND 9.7
is not backwards compatible.