Rough mechanism for identifying whether a locale is RTL

 Gotchas:
 1. Locale name must match directly (the lookup function doesn't fall back to parent locale if subtags are provided)
 2. (big) The RTL-containing locale must have a config file manually provided; this doesn't look up the base locales provided in the ember-i18n addon

 Next: add error handling if things are blank

[#LEI-348]

Author: abought

app/controllers/participate.js

@@ -0,0 +1,28 @@
+import Ember from 'ember';
+
+export default Ember.Controller.extend({
+    i18n: Ember.inject.service(),
+
+    // Set by login page
+    locale: null,
+
+    rtl: Ember.computed('i18n.locale', function() {
+        // Big assumption: any RTL locale we include MUST define the config manually! (can't seem to load the ember-18n config)
+
+        const locale = this.get('i18n.locale');
+        // TODO undefined check
+        const baseLocale = locale.split('-')[0];
+        // Ember i18n service doesn't expose config directly, so we fetch it in a manner analogous to `addTranslations`
+        // https://github.com/jamesarosen/ember-i18n/issues/375
+        // https://github.com/jamesarosen/ember-i18n/blob/a98bdaecebb0cddfa30ef98aacc032f38ac50ae5/addon/utils/add-translations.js#L6
+        const key = `locale:${baseLocale}/config`;  // TODO: check base translation code- this only works if locales explicitly define a config
+        const config = Ember.getOwner(this)._lookupFactory(key);
+        console.log('Found config!', config, config.rtl);
+        return config.rtl;
+    }),
+
+    init() {
+        // Services are lazily evaluated; make sure we can observe locale
+        this.get('i18n');
+    }
+});

app/locales/he/config.js

@@ -0,0 +1,16 @@
+// Ember-I18n includes configuration for common locales. Most users
+// can safely delete this file. Use it if you need to override behavior
+// for a locale or define behavior for a locale that Ember-I18n
+// doesn't know about.
+export default {
+    rtl: true,
+    //
+    // pluralForm: function(count) {
+    //   if (count === 0) { return 'zero'; }
+    //   if (count === 1) { return 'one'; }
+    //   if (count === 2) { return 'two'; }
+    //   if (count < 5) { return 'few'; }
+    //   if (count >= 5) { return 'many'; }
+    //   return 'other';
+    // }
+};