radiobutton: add missing (element-type) annotation for radio groups

The GSLists should specify their element-type in every annotation. We
are missing some.

https://bugzilla.gnome.org/show_bug.cgi?id=677127

gtk/gtkradiomenuitem.c

@@ -93,7 +93,8 @@ G_DEFINE_TYPE (GtkRadioMenuItem, gtk_radio_menu_item, GTK_TYPE_CHECK_MENU_ITEM)
 
 /**
  * gtk_radio_menu_item_new:
- * @group: the group to which the radio menu item is to be attached
+ * @group: (element-type GtkRadioMenuItem): the group to which the
+ *    radio menu item is to be attached
  *
  * Creates a new #GtkRadioMenuItem.
  *
@@ -155,7 +156,7 @@ gtk_radio_menu_item_get_property (GObject    *object,
 /**
  * gtk_radio_menu_item_set_group:
  * @radio_menu_item: a #GtkRadioMenuItem.
- * @group: the new group.
+ * @group: (element-type GtkRadioMenuItem): the new group.
  *
  * Sets the group of a radio menu item, or changes it.
  */
@@ -265,7 +266,7 @@ gtk_radio_menu_item_new_with_label (GSList *group,
 
 /**
  * gtk_radio_menu_item_new_with_mnemonic:
- * @group: group the radio menu item is inside
+ * @group: (element-type GtkRadioMenuItem): group the radio menu item is inside
  * @label: the text of the button, with an underscore in front of the
  *         mnemonic character
  *

gtk/gtkradiotoolbutton.c

@@ -151,8 +151,8 @@ gtk_radio_tool_button_new (GSList *group)
 
 /**
  * gtk_radio_tool_button_new_from_stock:
- * @group: (allow-none): an existing radio button group, or %NULL if you are
- *   creating a new group
+ * @group: (allow-none) (element-type GtkRadioButton): an existing radio button
+ *   group, or %NULL if you are creating a new group
  * @stock_id: the name of a stock item
  * 
  * Creates a new #GtkRadioToolButton, adding it to @group.