Queries that failed are cached for 5 seconds (NORR_TTL).
If the failure is local, like out of memory, it is not cached.
- the TTL comparison for the cache used different comparisons,
causing many cache responses that used the iterator and validator
state machines unnecessarily.
git-svn-id: file:///svn/unbound/trunk@1432 be551aaa-1e26-0410-a405-d3ace91eadb9