Forward-port of wrowe's NET_TIME filter removal/refactor into

the async-dev branch, in preparation for developing async write
completion in this branch on top of the new timeout design.
http://svn.apache.org/viewcvs.cgi?rev=306495&view=rev


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/async-dev@306541 13f79535-47bb-0310-9956-ffa450edef68