- Improve flushing/connection eos logic.

- Use brigade_write instead of immortal buckets that aren't immortal.
- Read HTTP status code from serf.
- Remove extra logging.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@759462 13f79535-47bb-0310-9956-ffa450edef68