backport HTTP strict processing from 2.4.x.

This backport is hand-constructed from many commits of HTTP strict,
subsequent fixes, as well as dependencies that hadn't been backported
to 2.2.x. 

The bulk is merged from httpd-2.4.x-merge-http-strict branch r1767941 - r1775671
Further details on httpd-2.2.x-merge-http-strict

Submitted By: sf, wrowe
Reviewed By: covener, ylavic, wrowe



git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.2.x@1777405 13f79535-47bb-0310-9956-ffa450edef68