* Rework TryToComplete.
Implement ability to complete challenge multiple times at once.
To do it, I split everything in checking/removing/rewarding steps.
In checking step, it calculates if it is possible to complete with minimal requirements and then calculates maximal repeating factor.
In removing step, it removes everything that is necessary.
In rewarding step, it give rewards by necessary factor (multilayer).
I rework item/block/entity removing as factors may be influenced at the last element, so I improve everything by memory usage. Create necessary sets/lists/queues for faster access to already collected items.
* Add method that returns removed items, if somehow algorithm did not manage to remove all items.
Fix issue when removeItems method did not merge ItemStacks as they had different item amount.
Return and fix TryToCompleteTest.
* Implement Multiple Challenge Completion command and GUI. (#73)
/[gamemode] challenges complete [number] allows to complete challenges [number] amount (or less if not enough items)
Via GUI users can right click on challenge and if it is repeatable, then it will open AnvilGUI that accepts only numbers as input.
- Implement LockedIcon in ChallengeLevel (can be null)
- Implement defaultLockedIcon in Settings (can be overwritten by ChallengeLevel)
- Reformat Config File. !!!
Rework methods that access to ChallengesPlayerData object. Methods that access to this object will be private and use UUID and String where possible.
Add public methods that could use previously mentioned methods to access ChallengesPlayerData object.
Implement these methods in all places.
Add ability to enable/disable island storage in config (no-gui for now).
Disable challenge GUI opening, if user does not have island.
Implement all methods that were only placeholders.
Remove all unnecessary old methods.
Implement new methods in all classes.
User and Admin command now opens new GUI.
Challenge now will not know their world, as it is not necessary.
Remove ICON type, as it is useless.
Rename Level to Other, as under it will be not only level things.
Rename slot to order, as it was weird that users could define slot but not order. Order is easier to understand and use.
ChallengesLevel now knows all their levels.
Each challenge level only will be for single world.
Rename some variables.
ChallengesPlayerData was just adapted with changes in challenges and level classes.
