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/helpers/highlight-words.js

@@ -1,18 +1,17 @@
 import Ember from 'ember';
 
 export default Ember.Handlebars.makeBoundHelper(function(text, phrase) {
-    if (phrase) {
-        var words = phrase.split(' ');
-        var replacement = function(matched) {
-            return '<span class="highlight-keyword">'+matched+'</span>';
-        };
-        words.forEach(function(word) {
-            text = text.replace(
-                new RegExp("\\b"+word+"\\b", 'gi'),
-                replacement
-            );
-        });
-    }
-    return new Ember.Handlebars.SafeString(text);
+  if (phrase) {
+    var words = phrase.split(' ');
+    var replacement = function(matched) {
+      return '<span class="highlight-keyword">'+matched+'</span>';
+    };
+    words.forEach(function(word) {
+      text = text.replace(
+        new RegExp("\\b"+word+"\\b", 'gi'),
+        replacement
+      );
+    });
+  }
+  return new Ember.Handlebars.SafeString(text);
 });
-