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/components/ui/action-button.js

@@ -0,0 +1,29 @@
+import Ember from 'ember';
+
+var precompileTemplate = Ember.Handlebars.compile;
+
+/**
+  Button which sends an action when clicked.
+ */
+export default Ember.Component.extend({
+  tagName: 'a',
+  attributeBindings: ['href', 'title'],
+  classNameBindings: ['className'],
+  href: '#',
+  layout: precompileTemplate('{{#if icon}}{{fa-icon icon class="fa-fw icon-glyph"}} {{/if}}<span>{{label}}</span>'),
+
+  label: '',
+  icon: '',
+  className: '',
+  action: null,
+
+  click: function(e) {
+    e.preventDefault();
+    var action = this.get('action');
+    if (typeof action === 'string') {
+      this.sendAction('action');
+    } else if (typeof action === 'function') {
+      action();
+    }
+  }
+});