refactor(formController): remove redundant methods from nullFormCtrl

Author: shahata

src/ng/directive/form.js

@@ -7,11 +7,8 @@ var nullFormCtrl = {
   $$renameControl: nullFormRenameControl,
   $removeControl: noop,
   $setValidity: noop,
-  $$setPending: noop,
   $setDirty: noop,
-  $setPristine: noop,
-  $setSubmitted: noop,
-  $$clearControlValidity: noop
+  $setSubmitted: noop
 },
 SUBMITTED_CLASS = 'ng-submitted';