Adds a border command to minetest to stop new players joining, an essential command in the server admins toolbox. Useful for preventing trolls returning repeatedly on different ip addresses, the border is maintained across server restarts and allows all your existing players transparent access.
/border
toggles the border, default is border open.
/visa <player>
opens a 24 hour window on the name supplied to allow a new player to join without dropping the border.