Make into a true polyfill

Fixes #5.

Why not patch in an initializer? Because then it wouldn't work in places like unit and integration tests.

addon/index.js

@@ -3,6 +3,10 @@ import FakeOwner from './fake-owner';
 
 let hasGetOwner = !!Ember.getOwner;
 
+Ember.deprecate("ember-getowner-polyfill is now a true polyfill. Use Ember.getOwner directly instead of importing from ember-getowner-polyfill", false, {
+  id: "ember-getowner-polyfill.import"
+});
+
 export default function(object) {
   let owner;
 

index.js

@@ -2,5 +2,25 @@
 'use strict';
 
 module.exports = {
-  name: 'ember-getowner-polyfill'
+  name: 'ember-getowner-polyfill',
+  included: function() {
+    this._ensureThisImport();
+    this.import('vendor/install-getowner-polyfill.js');
+  },
+  _ensureThisImport: function() {
+    if (!this.import) {
+      this._findHost = function findHostShim() {
+        var current = this;
+        var app;
+        do {
+          app = current.app || app;
+        } while (current.parent.parent && (current = current.parent));
+        return app;
+      };
+      this.import = function importShim(asset, options) {
+        var app = this._findHost();
+        app.import(asset, options);
+      };
+    }
+  }
 };

tests/unit/getowner-test.js

@@ -1,6 +1,6 @@
 import Ember from 'ember';
-import getOwner from 'ember-getowner-polyfill';
 import { moduleFor, test } from 'ember-qunit';
+const { getOwner } = Ember;
 
 moduleFor('foo:bar', {
   beforeEach() {

vendor/install-getowner-polyfill.js

@@ -0,0 +1,13 @@
+var Ember = require('ember').default;
+if (!Ember.getOwner) {
+  Object.defineProperty(Ember, 'getOwner', {
+    get: function() {
+      var FakeOwner = require('ember-getowner-polyfill/fake-owner').default;
+      return function(object) {
+        if (object.container) {
+          return new FakeOwner(object);
+        }
+      };
+    }
+  });
+}