Added new config options to deal with database timezone issues. Because ScreamingBedWars does not save timestamps yet to the database, these new config options are useful only when a timezone-related error prevents you from using the database.
database.add-timezone-to-connection-string, whether the timezone-id should be sent to the database server
database.timezone-id, defaults to the timezone of the machine
Fixed possible NPE during game start when invalid sign.yml file is loaded.
Added error logging when the plugin is not able to read statistics of a specific player from the YAML file
Fixed players seeing outdated statistics on holograms and leaderboards when using MySQL database with Bungee/Velocity network.