Prevent an Apache module from being loaded or added twice due
     to duplicate LoadModule or AddModule directives (or a missing
     ClearModuleList directive).

     LoadModule dupcheck (for 2.0) by Brian Pane <bpane@pacbell.net>
     Ported and added AddModule dupcheck by Will Rowe
     Identified by an old collegue of Will's who tripped over this.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/1.3.x@91836 13f79535-47bb-0310-9956-ffa450edef68