Refactor to avoid app/instance-initializers/ for Ember 1.11 support.

Due to an issue with ember-load-initializers we cannot have a file in
`app/instance-initializers/` when running against Ember < 1.12.

That is fixed upstream in ember-load-initializers#0.1.7, but is not
commonly in use yet.

---

For now, move this to the `addon/` dir and register it manually during
the main initializer.

addon/instance-initializers/ember-perf.js

@@ -0,0 +1,37 @@
+import Ember from 'ember';
+
+// this lives in addon/ because when running on Ember < 1.12
+// the ember-load-initializers project will attempt to call
+// `Ember.Application#instanceInitializer` which does not exist.
+//
+// This was fixed upstream in https://github.com/ember-cli/ember-load-initializers/pull/21,
+// but is not in widespread use yet.
+export function initialize(instance) {
+  // in 2.1 the ApplicationInstance instance has a public `lookup` method
+  const container = instance.lookup ? instance : instance.container;
+
+  // in 2.1 the ApplicationInstance uses `_lookupFactory` to avoid making lookupFactory public
+  // along with `lookup`
+  const config = container._lookupFactory ? container._lookupFactory('config:environment') : container.lookupFactory('service:ember-perf');
+  const emberPerfConfig = config.emberPerfConfig || {};
+
+  let shouldSubscribeToViewEvents = 'logViewEvents' in emberPerfConfig ? emberPerfConfig.logViewEvents : true;
+
+  if (shouldSubscribeToViewEvents) {
+    const emberPerf = container.lookup('service:ember-perf');
+
+    Ember.subscribe('render', {
+      before(name, timestamp, payload) {
+        emberPerf.renderBefore(name, timestamp, payload);
+      },
+      after(name, timestamp, payload) {
+        emberPerf.renderAfter(name, timestamp, payload);
+      }
+    });
+  }
+}
+
+export default {
+  name: 'ember-perf-instance-setup',
+  initialize
+};

app/initializers/ember-perf.js

@@ -1,13 +1,18 @@
+import Ember from 'ember';
 import EmberPerfService from 'ember-perf/services/ember-perf';
 import RouterExt from 'ember-perf/ext/router';
 import RouteExt from 'ember-perf/ext/route';
 import config from '../config/environment';
-import instanceInitializer from '../instance-initializers/ember-perf';
+import instanceInitializer from 'ember-perf/instance-initializers/ember-perf';
 
 const {
   Router, Route
 } = Ember;
 
+if (Ember.Application.instanceInitializer) {
+  Ember.Application.instanceInitializer(instanceInitializer);
+}
+
 function injectServiceOntoFactories(emberPerf, application) {
   const {
     injectionFactories