Create a new lock free circular queue, and use it in the EventMPM to remove...

Create a new lock free circular queue, and use it in the EventMPM to remove the timeout mutex that was wrapping both timeout queue operations and pollset operations.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1202257 13f79535-47bb-0310-9956-ffa450edef68