FLUSHing H2EOS and H2EOC buckets to preserve destruction order, improving...

FLUSHing H2EOS and H2EOC buckets to preserve destruction order, improving bucket beams to disengage from live green buckets on shutdown

git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1741045 13f79535-47bb-0310-9956-ffa450edef68