backport changes from 2.1:

- markup improvement
- Deletion of an incomprehensible sentence, because there is no 
  posibility not to choose the MPM at compile time.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.0.x@159286 13f79535-47bb-0310-9956-ffa450edef68