- Stations not disapearing when destroyed fixed

Added preview for spells:
- Spells are similar to enchantments, but are unique. An item can only have one spell on it, spells do not have levels, because they are made to do things that cannot be levelled. Also, spells can be switched on and off at any time.
- Right now spells can only be used through preview and are built-in the plugin, but later they will be fully customisable and modifiable.
- There are 3 built-in spells:
Telepathy (teleports all dropped items into your inventory when mining or killing mobs, applicable to tools and weapons)
Keeping (does not convent mined blocks as Silk Touck, applicable to tools)
Immunity (immunity to poison and wither effects, applicable to chestplate)

Commands:
- /ef preview enable - to enable spell preview (spells will not work in this command in not run)
- /ef preview spell add [key^] - to apply a spell to an item
- /ef preview spell remove - to remove the spell
- /ef preview spell switch - to enable or disable spells