public void addPluginListener( PluginListener listener )
    {
        pluginListeners.add( listener );
    }
Registers a PluginListener, which will now start receiving events regarding plugin creation and destruction.

When the listener was already registered, this method will have no effect.

@param listener the listener to be notified (cannot be null).
xmppserver/src/main/java/org/jivesoftware/openfire/container/PluginManager.java