【ItemFlip】 4.3.2

Fixed another ConcurrentModificationException

- Hopefully fixed ConcurrentModificationException

- Added two new settings

Settings:
  # If true gui will show up for both players, otherwise only for who clicked
  OpenGuiForBoth: true 

  # If true gui will open again if player closes GUI
  OpenGuiOnClose: true

Added %PREFIX% placeholder to messages.
Changed how the accept/decline buttons works. Now you can only accept game with buttons.

If you have accepted game and you add/remove item, state of the both players will change to declined.

Fixed dupe glitch

Fixed update notification missing link

Used TreeMap instead of HashMap so slots are now sorted automatically.

Added BlackListedMaterials under Settings section.

Added one new message regarding setting above.

Added options to change the text component of chat message:

TextComponent:
  First: "§7Click to"
  Second: " §a[Accept]"
  Third: "&a&lClick to accept ItemFlip"
  Four: " §c[Decline]"
  Five: "&c&lClick to decline ItemFlip"

Fixed bug in GUI

Updated Sound library

Added new options to disable plugin in specific gamemodes