Permission refinement

+ Default world permissions
» Added 2 new config options: world.default.permission.public and world.default.permission.public
» Each option sets the default permission the respected world type will have when created
» Use %world% as a placeholder for the world's name

+ Restrict commands to world creator
» All commands defaults to .self when no suffix (.self, .other) is provided. For example: buildsystem.day = buildsystem.day.self
» With the permission suffix .self, a player can only modify worlds that belong to the player (player is creator)
» With the permission suffix .other, a player can only modify worlds that don't belong to the player (player is not creator)

+ More permission checks when using /worlds edit
» Each task found in /worlds edit now has an extra sub-permission to restrict tasks to certain players.
» A list of all permissions can be found here: https://buildsystem.eintosti.com/worlds/edit/

Thanks a lot to @EinJOJO for coding a large amount of the update.