Hotfix of challenges

Contains:

• Hotfix of challenges
• Better documentation in .yml files
• Automagical WorldGuard region creation
• Working /is restart (enderchest, armor and inventory)
• /dev renamed to /usb
• /usb remove now removes the island
• /is info now shows more info
• completing challenges now tells the missing items
• Option of adding a radius to onIsland challenges
• Performance improvement - loading of data is postponed, and not on player-join
• ... and more - for a complete list, checkout GitHub.