xhtml_style: add methods for translation

do nothing, but at least makes gadget compatible

See discussion on
nexedi/erp5@a7ffbc92 (comment 81088)

product/ERP5/bootstrap/erp5_xhtml_style/SkinTemplateItem/portal_skins/erp5_xhtml_style/erp5_gadgetfield.js.js

@@ -69,6 +69,17 @@
         return displayFieldError(argument_list[0]);
       })
 
+    .allowPublicAcquisition('translateHtml', function dummyTranslateHtml (html) {
+        // gadget translation does not work in erp5_xhtml_style, but at least
+        // gadgets can be used.
+        return html;
+      })
+    .allowPublicAcquisition('translate', function dummyTranslate (html) {
+        // gadget translation does not work in erp5_xhtml_style, but at least
+        // gadgets can be used.
+        return html;
+      })
+
     /////////////////////////////////////////////////////////////////
     // declared methods
     /////////////////////////////////////////////////////////////////