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!

framework/core/ember/tests/index.html

@@ -13,22 +13,6 @@
     <link rel="stylesheet" href="assets/vendor.css">
     <link rel="stylesheet" href="assets/flarum.css">
     <link rel="stylesheet" href="assets/test-support.css">
-    <style>
-      #ember-testing-container {
-        position: absolute;
-        background: white;
-        bottom: 0;
-        right: 0;
-        width: 640px;
-        height: 384px;
-        overflow: auto;
-        z-index: 9999;
-        border: 1px solid #ccc;
-      }
-      #ember-testing {
-        zoom: 50%;
-      }
-    </style>
 
     {{content-for 'head-footer'}}
     {{content-for 'test-head-footer'}}

framework/core/ember/tests/test-helper.js

@@ -4,9 +4,3 @@ import {
 } from 'ember-qunit';
 
 setResolver(resolver);
-
-document.write('<div id="ember-testing-container"><div id="ember-testing"></div></div>');
-
-QUnit.config.urlConfig.push({ id: 'nocontainer', label: 'Hide container'});
-var containerVisibility = QUnit.urlParams.nocontainer ? 'hidden' : 'visible';
-document.getElementById('ember-testing-container').style.visibility = containerVisibility;