FIX of nullpointer error when you click on empty slot in GUI

FIX when you click to delete the item, now he is correctly delete

NEW No need to set quantity for the command /ei-give (default is 1) (Idea of Bard)

NEW item option: needConfirmBeforeUse: true/false (by default its false) the player need to double click to use this item (Idea of Kej$i)

NEW enchantments support exemple here (Idea of Gabo): https://github.com/ssomar1607/ExecutableItems/wiki IN GUI SET {enchant}:{level}

NEW if you do the /ei-create with item in your hand, it take the lore, the name and the enchants of this item and add automaticly to your new item