Merge pull request emberjs#3423 from goshakkk/text-support-readonly

Add a 'readonly' binding to TextSupport

Author: stefanpenner

packages/ember-handlebars/lib/controls/text_support.js

@@ -18,7 +18,7 @@ var get = Ember.get, set = Ember.set;
 Ember.TextSupport = Ember.Mixin.create({
   value: "",
 
-  attributeBindings: ['placeholder', 'disabled', 'maxlength', 'tabindex'],
+  attributeBindings: ['placeholder', 'disabled', 'maxlength', 'tabindex', 'readonly'],
   placeholder: null,
   disabled: false,
   maxlength: null,