Ember 2.1 Compatibility

 * rely on helper lookup for `{{t}}` instead of manual registration
   for Ember 1.13+
 * use `container.registry` when it's available, falling back to the
   older, private `container._registry`

addon/utils/add-translations.js

@@ -8,7 +8,8 @@ export default function addTranslations(locale, newTranslations, container) {
     existingTranslations = {};
     // CRUFT: there's no public API for registering factories at runtime.
     // See http://discuss.emberjs.com/t/whats-the-correct-way-to-register-new-factories-at-runtime/8018
-    container._registry.register(key, existingTranslations);
+    const registry = container.registry || container._registry;
+    registry.register(key, existingTranslations);
   }
 
   Ember.merge(existingTranslations, newTranslations);

app/helpers/t.js

@@ -0,0 +1 @@
+export { default } from 'ember-i18n/helper';

app/instance-initializers/ember-i18n.js

@@ -1,6 +1,5 @@
 import Ember from "ember";
 import legacyHelper from "ember-i18n/legacy-helper";
-import Helper from "ember-i18n/helper";
 import ENV from '../config/environment';
 
 export default {
@@ -17,9 +16,5 @@ export default {
     if (legacyHelper != null) {
       Ember.HTMLBars._registerHelper('t', legacyHelper);
     }
-
-    if (Helper != null) {
-      instance.registry.register('helper:t', Helper);
-    }
   }
 };