Add user and permission system

Add users, roles and permissions and rework the authentication to use
separate user and slave tokens for control and slave connections
respectively.

Add commands for listing permissions, roles and users, and creating,
editing and deleting roles and users.

modules/clusterio/impl.lua

@@ -23,6 +23,16 @@ impl.events[api.events.on_server_startup] = function()
     game.disable_replay()
 end
 
+impl.events[defines.events.on_player_joined_game] = function(event)
+    local player = game.players[event.player_index]
+    api.send_json("player_event", { type = "join", name = player.name })
+end
+
+impl.events[defines.events.on_player_left_game] = function(event)
+    local player = game.players[event.player_index]
+    api.send_json("player_event", { type = "leave", name = player.name })
+end
+
 -- Internal API
 clusterio_private = {}
 function clusterio_private.update_instance(new_id, new_name)