add RadioButton Lua class

res/layouts/pages/settings.xml.lua

@@ -3,15 +3,13 @@ function on_open()
         "%s: %s", gui.str("Language", "settings"),
         gui.get_locales_info()[core.get_setting("ui.language")].name
     )
-    set_page("s_gfx", "settings_graphics")
-end
-
-function set_page(btn, page)
-    document.s_aud.enabled = true
-    document.s_dsp.enabled = true
-    document.s_gfx.enabled = true
-    document.s_ctl.enabled = true
-    document.s_rst.enabled = true
-    document[btn].enabled = false
-    document.menu.page = page
+    sections = RadioGroup({
+        audio=document.s_aud,
+        display=document.s_dsp,
+        graphics=document.s_gfx,
+        controls=document.s_ctl,
+        reset=document.s_rst
+    }, function (page)
+        document.menu.page = "settings_"..page
+    end, "graphics")
 end