Added more restrictions.
Added ender pearl restriction.
Added elytra restriction.
Added option to configure slots in the GUI. please reset your language.yml when you update the plugin otherwise the GUI will break.
Fixed small mem leak
Fixed glowing not working in the menu
Fixed that duel requests could be replaced if another player requested same player
Removed storing secondRequest. it wasn't needed and was taking 2x more space in the requests.
Removed another useless list.