Merge r1524192, r1524770, r1527925, r1541270, r1541368 from trunk:

Merge r1524192, r1524770, r1527925, r1541270, r1541368 from trunk:

Update rationale

draft-ietf-httpbis-p1-messaging-23 fixes regarding interactions
between TE and content-length in the same req/resp.

PR 55616 (add missing APLOGNO), part 1

Wrap at 80 still, here at httpd project

Use a distinguishing APLOGNO for unk t-e with read-until-close behavior
Submitted by: jim, kbrand, wrowe, wrowe
Reviewed/backported by: jim

git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.4.x@1575934 13f79535-47bb-0310-9956-ffa450edef68