Implement a new timer scheme which eliminates the need to call alarm() all

the time.  Instead a counter in the scoreboard for each child is used to
show when the child has made forward progress.  The parent samples this
counter every scoreboard maintenance cycle, and issues SIGALRM if no
progress has been made in the timeout period.  This reduces the static
request best-case syscall count to 22 from 29.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/1.3.x@78978 13f79535-47bb-0310-9956-ffa450edef68