int connect_simple_after(string signal
, callback callback
[, mixed userparam
Connects a signal to the given callback. The first callback parameter
(the object it has been called on) is omitted.
Further, the handler will be called only after all non-after handlers
have been activated.
The method returns a signal handler id that
can be used to block() or
disconnect() the handler.
For more information about signals, see the
Signal Handling tutorial