Backport r230735, we need not look at the first bucket for EOS, 
  because the outer while loop protected us from that case.  

  Backport the header brigade changes as it's impossible to have
  a body request waiting for a final send.  Look at seen_eos to 
  flush us in the request body loop, and handle the only exception,
  (header_brigade), outside of that loop.

  This brings stream_reqbody_cl in sync with the trunk.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/proxy-reqbody-2.0.x@230736 13f79535-47bb-0310-9956-ffa450edef68