Upgrade to Ember 1.11-beta.1

HTMLBars goodness! Since there was some breakage and a lot of fiddling
around to get some things working, I took this opportunity to do a big
cleanup of the whole Ember app. I accidentally worked on some new
features too :3

Note that the app is still broken right now, pending on
https://github.com/emberjs/ember.js/issues/10401

Cleanup:
- Restructuring of components
- Consolidation of some stuff into mixins, cleanup of some APIs that
will be public
- Change all instances of .property() / .observes() / .on() to
Ember.computed() / Ember.observer() / Ember.on() respectively (I think
it is more readable)
- More comments
- Start conforming to a code style (2 spaces for indentation)

New features:
- Post hiding/restoring
- Mark individual discussions as read by clicking
- Clicking on a read discussion jumps to the end
- Mark all discussions as read
- Progressively mark the discussion as read as the page is scrolled
- Unordered list post formatting
- Post permalink popup

Demo once that Ember regression is fixed!

ember/app/adapters/application.js

@@ -1,24 +1,38 @@
 import DS from 'ember-data';
 import JsonApiAdapter from 'ember-json-api/json-api-adapter';
-import config from '../config/environment';
+
+import config from 'flarum/config/environment';
+import AlertMessage from 'flarum/components/ui/alert-message';
 
 export default JsonApiAdapter.extend({
   host: config.apiURL,
 
   ajaxError: function(jqXHR) {
     var errors = this._super(jqXHR);
+
+    // Reparse the errors in accordance with the JSON-API spec to fit with
+    // Ember Data style. Hopefully something like this will eventually be a
+    // part of the JsonApiAdapter.
     if (errors instanceof DS.InvalidError) {
       var newErrors = {};
       for (var i in errors.errors) {
         var error = errors.errors[i];
         newErrors[error.path] = error.detail;
       }
-      errors = new DS.InvalidError(newErrors);
-    } else if (errors instanceof JsonApiAdapter.ServerError) {
-      // @todo show an alert message
-      console.log(errors);
+      return new DS.InvalidError(newErrors);
     }
+
+    // If it's a server error, show an alert message. The alerts controller
+    // has been injected into this adapter.
+    if (errors instanceof JsonApiAdapter.ServerError) {
+      var message = AlertMessage.create({
+        type: 'warning',
+        message: errors.message
+      });
+      this.get('alerts').send('alert', message);
+      return;
+    }
+
     return errors;
   }
-  
 });