Add ConfigManager and fix bugs(now it works)

Tested on 1.12.2 (may work on 1.9-1.12)

• Config files are in "plugins/SuperItem/configs' with the name "{ItemPackage} : {item}.json"
• Now Superitem Script(superitem.kts) works

//example as Flame_Axe.superitem.kts
import org.bukkit.Material 
import org.bukkit.enchantments.Enchantment 
import org.bukkit.entity.Player 
import org.bukkit.event.EventHandler 
import org.bukkit.event.EventPriority 
import org.bukkit.event.entity.EntityDamageByEntityEvent 
 
require(ItemInfo(Material.IRON_AXE, "§4FLAMES AXE", listOf("§3 Use wisely")) { im, _ -> 
    im.addEnchant(Enchantment.FIRE_ASPECT, 2, false) 
    im.addEnchant(Enchantment.DAMAGE_ALL, 4, false) 
}) 
 
require(CoolDown(600)) 
require(Recipe("2@0;377;399;377;258;377;399;377;0")) 
listen<EntityDamageByEntityEvent>(priority = EventPriority.HIGHEST){e-> 
    if (e.damager is Player) { 
        val p = e.damager as Player 
        if (isItem(p.inventory.itemInMainHand)) { 
            if (get<Permission>().hasPermission(p) && get<CoolDown>().isCoolDownOK(p)) { 
                get<CoolDown>().add(p) 
            } else 
                e.damage = 1.0 
        } 
    } 
}