Merge r580437 from trunk:

Share a single write-pipe handle for piped stderr logging, this
prevents an extra logging process from hanging around after the
initial config-phase.

Reviewed by: rpluem, wrowe
Submitted by: wrowe
Reviewed by: jim


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.0.x@603921 13f79535-47bb-0310-9956-ffa450edef68