Sets the action(s) that the specified mouse button will have
on the CList.
WARNING: gtk_clist_set_button_actions is deprecated and should not be used in newly-written code.
The mouse button to set. The values here, unlike in the
rest of GTK+ start from 0. For instance, the right mouse
button, which is 3 elsewhere, should be given as 2 here.
button.actions
A logically OR'd value of GtkButtonAction values
for the button.