Rename "mt_irc" namespace to "irc"

The underlying IRC library is now available as irc.lib.

API.md

@@ -0,0 +1,89 @@
+IRC Mod API
+===========
+
+This file documents the Minetest IRC mod API.
+
+Basics
+------
+
+In order to allow your mod to interface with this mod, you must add `irc`
+to your mod's `depends.txt` file.
+
+
+Reference
+---------
+
+irc:say([name,] message)
+Sends <message> to either the channel (if <name> is nil or not specified),
+or to the given user (if <name> is specified).
+Example:
+	irc:say("Hello, Channel!")
+	irc:say("john1234", "How are you?")
+
+irc:register_bot_command(name, cmdDef)
+	Registers a new bot command named <name>.
+	When an user sends a private message to the bot with the command name, the
+	command's function is called.
+	Here's the format of a command definition (<cmdDef>):
+	cmdDef = {
+		params = "<param1> ...",      -- A description of the command's parameters
+		description = "My command",   -- A description of what the command does. (one-liner)
+		func = function(user, param)
+			-- This function gets called when the command is invoked.
+			-- <user> is a user table for the user that ran the command.
+			--   (See the LuaIRC documentation for details.)
+			--   It contains fields such as 'nick' and 'ident'
+			-- <param> is a string of parameters to the command (may be "")
+		end,
+	};
+	Example:
+	irc:register_bot_command("hello", {
+		params = "",
+		description = "Greet user",
+		func = function(user, param)
+			irc:say(user.nick, "Hello!")
+		end,
+	});
+
+irc.joined_players[name]
+	This table holds the players who are currently on the channel (may be less
+	than the players in the game). It is modified by the /part and /join chat
+	commands.
+	Example:
+	if irc.joined_players["joe"] then
+		-- Joe is talking on IRC
+	end
+
+irc:register_hook(name, func)
+	Registers a function to be called when an event happens. <name> is the name
+	of the event, and <func> is the function to be called. See HOOKS below
+	for more information
+	Example:
+	irc:register_hook("OnSend", function(line)
+		print("SEND: "..line)
+	end)
+
+This mod also supplies some utility functions:
+
+string.expandvars(string, vars)
+	Expands all occurrences of the pattern "$(varname)" with the value of
+	'varname' in the <vars> table. Variable names not found on the table
+	are left verbatim in the string.
+	Example:
+	local tpl = "$(foo) $(bar) $(baz)"
+	local s = tpl:expandvars({foo=1, bar="Hello"})
+	assert(s == "1 Hello $(baz)") 
+
+In addition, all the configuration options decribed in `README.txt` are
+available to other mods, though they should be considered read-only. Do
+not modify these settings at runtime or you might crash the server!
+
+
+Hooks
+-----
+
+The `irc:register_hook` function can register functions to be called
+when some events happen. The events supported are the same as the LuaIRC
+ones with a few added (mostly for internal use).
+See src/LuaIRC/doc/irc.luadoc for more information.
+