:response_cache plugin is now more compliant with how the RFC 2616 defines which behaviour caches shall have:
it caches only responses with one of the following status codes: 200, 203, 300, 301, 410.
it discards cached responses which become stale.
it supports “cache-control” header directives to decided when to cache, to store, what the response “age” is.
it can cache more than one response for the same request, provided that the request presents different header values for the headers declared in the “vary” response header (previously, it was only caching the first response, and discarding the remainder).
fixed DNS resolution bug which caused a loop when a failed connection attempt would cause a new DNS request to be triggered for the same domain, filling up and giving preference to the very IP which failed the attempt.
response_cache: request verb is now taken into account, not causing HEAD/GET confusion for the same URL.