code: public JwwfServer attachPlugin(JwwfPlugin plugin) {
  		plugins.add(plugin);
  		if (plugin instanceof IPluginGlobal)
  			((IPluginGlobal) plugin).onAttach(this);
  		return this;
  	}
docs: Attahes new plugin to this server
  
  @param plugin Plugin to attach
  @return This JwwfServer