Connecting to spin buttons

[Geoff Finger <gfinger cravegames com>]

What kind of signals do spin buttons emit?

(More general question, is there an index somewhere that lists all signals
that all widgets emit?)

I would like to use two sets of spin buttons to control the position of a
image in another window. However I need some way to figure out when the
value has been changed. 

I tried catching "clicked" from the spinner to no result, and tried
catching "value_changed" from the adjustment object with disasterous
results.

Idealy I'd like to know a signal emited when you either clicked up or down
or changed the value by hand. However I can just do two functions if they
have two different signals.

Thanks