Correct widget from gtk_action_create_tool_item on GtkRadioAction

[Michael Ekstrand <mekstran scl ameslab gov>]

In attempting to work out some stuff involving GtkRadioAction's, I  
stumbled across some initially surprising behavior.  Requesting a  
tool item from a GtkRadioAction does *not* produce a  
GtkRadioToolButton, but rather a GtkToggleToolButton.

It seemed to me that this is likely because a GtkRadioToolButton  
would wind up having two GtkRadioButtonGroup's fighting for control  
over the selection (since both the actions and the widgets would  
belong to groups).

Is this correct, and is GTK+ doing the right thing here?  Or is there  
some other explanation and a strange bug?

- Michael