Major cleanup.

- Use `irc.foo` notation instead of `irc:foo`. It still
  supports the `irc:foo` usage, but will helpfully issue
  a warning with the location of the offending code.
- Remove unused arguments from functions.

player_part.lua

@@ -2,19 +2,19 @@
 -- See LICENSE.txt for details.
 
 
-function irc:player_part(name)
-	if not self.joined_players[name] then
+function irc.player_part(name)
+	if not irc.joined_players[name] then
 		return false, "You are not in the channel"
 	end
-	self.joined_players[name] = nil
+	irc.joined_players[name] = nil
 	return true, "You left the channel"
 end
 
-function irc:player_join(name)
-	if self.joined_players[name] then
+function irc.player_join(name)
+	if irc.joined_players[name] then
 		return false, "You are already in the channel"
 	end
-	self.joined_players[name] = true
+	irc.joined_players[name] = true
 	return true, "You joined the channel"
 end
 
@@ -22,23 +22,23 @@ end
 minetest.register_chatcommand("join", {
 	description = "Join the IRC channel",
 	privs = {shout=true},
-	func = function(name, param)
-		return irc:player_join(name)
+	func = function(name)
+		return irc.player_join(name)
 	end
 })
 
 minetest.register_chatcommand("part", {
 	description = "Part the IRC channel",
 	privs = {shout=true},
-	func = function(name, param)
-		return irc:player_part(name)
+	func = function(name)
+		return irc.player_part(name)
 	end
 })
 
 minetest.register_chatcommand("who", {
 	description = "Tell who is currently on the channel",
 	privs = {},
-	func = function(name, param)
+	func = function()
 		local out, n = { }, 0
 		for plname in pairs(irc.joined_players) do
 			n = n + 1
@@ -61,9 +61,9 @@ minetest.register_on_leaveplayer(function(player)
 	irc.joined_players[name] = nil
 end)
 
-function irc:sendLocal(message)
-	for name, _ in pairs(self.joined_players) do
+function irc.sendLocal(message)
+	for name, _ in pairs(irc.joined_players) do
 		minetest.chat_send_player(name, message)
 	end
-	irc:logChat(message)
+	irc.logChat(message)
 end