Fixed race condition in async response processing in pipelining mode

git-svn-id: https://svn.apache.org/repos/asf/httpcomponents/httpcore/trunk@1594528 13f79535-47bb-0310-9956-ffa450edef68
Minor performance optimization tweak for pipelining mode

git-svn-id: https://svn.apache.org/repos/asf/httpcomponents/httpcore/trunk@1594529 13f79535-47bb-0310-9956-ffa450edef68
Work in progress
Work in progress