+6357. [func] The QP zone database implementation introduced in
+ change #6355 has now been replaced with a version
+ based on the multithreaded dns_qpmulti API, which
+ is based on RCU and reduces the need for locking.
+ The new implementation is called "qpzone". The
+ previous "qp" implementation has been renamed
+ "qpcache", and can only be used for the cache.
+ [GL #4348]
+
6356. [bug] Attach the loop also in the dns_cache_flush(), so
the cache pruning still works after the flush.
[GL #4621]