UdnPwdDirAuth authentication plugin instance is not working.
Ticket #1579 : UdnPwdDirAuth authentication plugin instance is not working.
Since this class no longer works, we felt it best to just remove it from the server.
This patch removes the references and files associated with this auth method,including
the plugin
itself, so intrepid individuals will not be tempted to manually configure this auth
method.
QE has nicely decided to independently remove the tests associated with this plugin
already.