Made this cause I hate stuff beeping at me and prefer visual notification.
This also handles notify.pl not firing while you're actually focused on
the clients terminal window (hence the small modification).

notify.pl slightly modified so it receives for 'focus change' signals
and has a setting variable notify_enabled so it can be turned on/off
explicitly.

scripts under extern/ are scripts I use unmodified.

Dependancies:
systemtray.pl requires gtk2-trayicon perl bindings.
notify.pl requires libnotify-bin as it uses notify-send.
focus.pl will only work inside X.
url.pl requires URI::Find package from cpan. 

Commands and Options:
focus.pl commands:
	/focus_get_new_id
		Get currently focused window id and use that for
		tracking.

systemtray.pl options:
boolean - systemtray_update - default: on
		Actually process data levels and focus.
		Should really seperate them into seperate options.

boolean - systemtray_goto_status - default: on
		Go to the status page so all channels can highlight
		to provide correct data level inspection.
		The currently focused channel doesn't change
		data levels.

url.pl options:
string - url_browser - default: x-www-browser
		the browser to open the url

int - url_max_id - default: 40
		the maximum number of urls to track
		once id == url_max_id it rolls over to zero
		overwriting old urls

url.pl commands:
	/url <id>
		open url with id <id>

Bugs/Issues

This cannot track focus through screen, say you create in one window;
destroy it and reattach to screen in another. focus tracking won't work
as the window id is now invalid; use /focus_get_new_id to get the latest.
Maybe that can be automated?

Launching irssi in a terminal that doesn't have focus won't work. When launching
it thinks the currently active window has focus. again use /focus_get_new_id to
fix.

Probably some more I can't think of...