Lucky Cases

Huge update:

1. Completely rewritten case addition system: you can now add new cases in the conig edit and remove default cases.
2. Added a lot more stuff to configurate in config.
3. It is now possible to get attribute modifiers on your recieved items, you can change this in your config.
4. Added 3 new cases
5. Cases are no longer stackable :(
6. Because of the new case system, all cases have been replaced, so your current ones will be gone.
7. Gui improvements
8. Added a chat message, which can be seen by everybody, when a player opened a case. This can be turned of in the config
9. A lot more...