REFACTOR: Allow `radio-button` component to be disabled.

app/assets/javascripts/discourse/components/radio-button.js.es6

@@ -1,11 +1,16 @@
+import computed from "ember-addons/ember-computed-decorators";
+
 export default Ember.Component.extend({
   tagName : "input",
   type : "radio",
-  attributeBindings : [ "name", "type", "value", "checked:checked" ],
+  attributeBindings : ["name", "type", "value", "checked:checked", "disabled:disabled"],
+
   click : function() {
     this.set("selection", this.$().val());
   },
-  checked : function() {
-    return this.get("value") === this.get("selection");
-  }.property('selection'),
+
+  @computed('value', 'selection')
+  checked(value, selection) {
+    return value === selection;
+  },
 });