Merge r480135, r480193, r504559, r602349, r602657, r503863 from trunk:

* Apply patch for PR 41056 (19954) to fix chunk
  filter. Now flushes work better.

* Protect against any sort of non-block read that
  would block. If ap_get_brigade() shows that, return
  EAGAIN.

* Further refinement for PR41056 / PR 19954 (mostly-fixed in r480135.)
  We assume that a successful read but an empty brigade
  is NOT cause for EAGAIN. Testing may or may not
  confirm this assumption, in which case that test
  may be required as well.

* If no data is available at this point of time we need to switch into the
  BODY_CHUNK_PART state like we do several lines later in the code in the
  same situation.

* Case statements should go on their own line.  (No functional change.)

* modules/http/http_filters.c
  (ap_http_filter): Put case on its own line.

* Add missing Changelog entry for PR41056 / PR 19954. This was fixed in r480135.

PR: 41056 / 19954
Submitted by: jfclere, jim
Reviewed by: rpluem, jim, jerenkrantz


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.2.x@602679 13f79535-47bb-0310-9956-ffa450edef68