Add gtk_radio_button_set_value(), gtk_radio_button_get_current_value() and

Add gtk_radio_button_set_value(), gtk_radio_button_get_current_value() and

2007-06-04  Emmanuele Bassi  <ebassi@gnome.org>

	* gtk/gtkradiobutton.h:
	* gtk/gtkradiobutton.c:
	* gtk/gtk.symbols: Add gtk_radio_button_set_value(),
	gtk_radio_button_get_current_value() and gtk_radio_button_get_value().
	Use these functions to set and get an arbitrary integer associated to
	a GtkRadioButton in a group, like the value associated to a
	GtkRadioAction.

	* tests/testgtk.c:
	(create_radio_buttons), (radio_toggled_cb): Exercise the new API.

svn path=/trunk/; revision=18019