patch to 8.2.3-REL to deny queries w/o sending a refusal response

[Peter Koch]

> My silent-deny patch only prevents a response when it would be a refusal. 
> Normal queries will be unimpeded.

Given a configuration where allow-query is set to 'none' by default and
reopened for every single zone served on the nameserver. If the server
is delegated lame a certain zone, with current behaviour any querier will
receive a 'refused' message while with your patch applied they receive no
answer at all, correct?
I just wonder whether this is good for fighting lame delegations or bad
for them being detected.

-Peter