Fix lingering close (and make it more efficient). We were blocking on

Fix lingering close (and make it more efficient). We were blocking on
apr_read() for 30 seconds for each lingering close. What we want to
do is block for 2 seconds. If we do not read any bytes from the client
in that time, close the connection. If we do read bytes, then wait 2
more seconds to see if more arrive, etc. Repeat for MAX_SECS_TO_LINGER
if needed.

This should clear the way to get 2.0 running on apache.org!

git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@88167 13f79535-47bb-0310-9956-ffa450edef68