More customizations

• Allow customizing the kick message that override all other ones
• Allow tweaking the falling blocks per chunk limit
• Allow tweaking the xp bottle per chunk limit
• Remove FixWorldStatsCommandBug because you should be using my WorldStatsRewritten plugin instead.
• Add beacon per chunk limit
• Disable ExperimentalDupePatch2 by default due to a load of bugs.
• Add another check to the falling blocks prevention to hopefully prevent some lag.
• Clean up event registering (#16)