IRC events
~~~~~~~~~~
Incoming IRC server messages are delivered in 4 stages, by calling the
following fungw registered functions in all scripts, in this order:

pre_CMD()
on_CMD()
<hardwired C command handlers, mostly printing things>
post_CMD()

The order of execution within a stage is random. If the pre_ or on_ stage
calls hook_block(), the next stages are not ran. 

CMD is a standard irc command, e.g. privmsg, join, kick or numerics like 433.
Incoming CTCP requests and responses are stripped off of the \001 marks and
are renamed to ctcp_req or ctcp_resp - the former is the privmsg variant and
the latter is the notice variant. So to capture CTCP requests, register a
function called on_ctcp_req().

Irc events are delivered to functions with two args:

function pre_433(from, argc)

where from is a string that is a nickname or server name (originator of the
message/command) and argc is an integer number of arguments the command has.
Command arguments can be queried using function hook_arg(0) .. hook_arg(argc-1).
Further details of the origin of the command can be queried with the following
calls (without argument):
	hook_from_nick()   - same as the from argument above
	hook_from_ident()  - the ident of the sender, if it is a nick (else empty string)
	hook_from_host()   - the hostname of the sender, if it is a nick (else empty string)
	hook_from_hostmask - the hostmask of the sender in nick!ident@host format


Misc events
~~~~~~~~~~~

on_query_alloc(server_id, nickname)
	Incoming message without window; server_id is an integer and nickname is
	a string. The caller will search for a window again after the call so the
	script has a chance to allocate one. Note: the script needs to check if
	another script did not allocate a window already.

on_tick_second()
	Called once a second.

on_tick_minute()
	Called once a minute.