void on_talk( string message, object actor, object target )

Called whenever speech is heard. Should be called in inanimate objects as
well. The 'message' is the text spoken, the 'actor' is the one doing
the talking and should always be an object, and the 'target' is the one
being spoken to. The target is often 0.

FOR SCRIPTS: on_talk

Called whenever speech is heard. Actor is the one speaking, Target is the one
being spoken to (often 0), and Message is the actual text being spoken.
