Merge r630335, r630348, r630350 from trunk:

Merge r630335, r630348, r630350 from trunk:

Worker MPM: fix race condition
PR44402: reported and fixed by Basant Kumar Kukreja

* Second part of fix for PR 44402:

  - Fix the same race condition in event MPM.
  - Slightly optimize code in worker MPM by removing the need for an additional
    dereference operation.
  - Do some word smithing on the CHANGES entry.

PR: 44402
Submitted by: Basant Kumar Kukreja <basant.kukreja sun.com>
Reviewed by: rpluem

* Add hint to PR in comment. No functional change.

Reviewed by: jim

git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.2.x@631362 13f79535-47bb-0310-9956-ffa450edef68