Refactor releasing the child processes by eliminating the

time lookup, eliminating the bogus/misimplemented function,
and introducing fairness to release any dead threads before
getting hung up on releasing longer lived threads.

Also pick up the time-to-wait from the server global timeout.

And finally, axe a completely bogus internal helper function.

Backports: r573103, r573105

git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.0.x@607310 13f79535-47bb-0310-9956-ffa450edef68