Merge r892678, r1100511, r1102124 from trunk:

Merge r892678, r1100511, r1102124 from trunk:

Reject requests containing (invalid) NULL characters in request line
or request headers.
PR 43039

use APR_STATUS_IS_TIMEUP() instead of direct comparison with APR_TIMEUP.

Use APR_STATUS_IS_... in some more cases.

While this is not strictly necessary everywhere, it makes it much easier
to find the problematic cases.

Submitted by: niq, covener, sf
Reviewed  by: wrowe, covener, ylavic

git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.2.x@1758671 13f79535-47bb-0310-9956-ffa450edef68