Correct the approach to std file handles by simplifying the approach

and taking better advantage of apr's now-proper support.

Already verified by Randy Kobes and Tom Donovan

Sync to trunk r580433

git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.0.x@607302 13f79535-47bb-0310-9956-ffa450edef68