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/models/discussion.js

@@ -1,48 +1,49 @@
 import Ember from 'ember';
 import DS from 'ember-data';
 
-var Discussion = DS.Model.extend({
+export default DS.Model.extend({
+  title: DS.attr('string'),
+  slug: Ember.computed('title', function() {
+    return this.get('title').toLowerCase().replace(/[^a-z0-9]/gi, '-').replace(/-+/g, '-');
+  }),
 
-	title: DS.attr('string'),
-	content: DS.attr('string'), // only used to save a new discussion
+  startTime: DS.attr('date'),
+  startUser: DS.belongsTo('user'),
+  startPost: DS.belongsTo('post'),
 
-	slug: function() {
-		return this.get('title').toLowerCase().replace(/[^a-z0-9]/gi, '-').replace(/-+/g, '-');
-	}.property('title'),
-	
-	canReply: DS.attr('boolean'),
-	canEdit: DS.attr('boolean'),
-	canDelete: DS.attr('boolean'),
+  lastTime: DS.attr('date'),
+  lastUser: DS.belongsTo('user'),
+  lastPost: DS.belongsTo('post'),
+  lastPostNumber: DS.attr('number'),
 
-	startTime: DS.attr('date'),
-	startUser: DS.belongsTo('user'),
-	startPost: DS.belongsTo('post'),
+  canReply: DS.attr('boolean'),
+  canEdit: DS.attr('boolean'),
+  canDelete: DS.attr('boolean'),
 
-	lastTime: DS.attr('date'),
-	lastUser: DS.belongsTo('user'),
-	lastPost: DS.belongsTo('post'),
-	lastPostNumber: DS.attr('number'),
+  commentsCount: DS.attr('number'),
+  repliesCount: Ember.computed('commentsCount', function() {
+    return Math.max(0, this.get('commentsCount') - 1);
+  }),
 
-	relevantPosts: DS.hasMany('post'),
+  // The API returns the `posts` relationship as a list of IDs. To hydrate a
+  // post-stream object, we're only interested in obtaining a list of IDs, so
+  // we make it a string and then split it by comma. Instead, we'll put a
+  // relationship on `loadedPosts`.
+  posts: DS.attr('string'),
+  postIds: Ember.computed('posts', function() {
+    var posts = this.get('posts') || '';
+    return posts.split(',');
+  }),
+  loadedPosts: DS.hasMany('post'),
+  relevantPosts: DS.hasMany('post'),
 
-	commentsCount: DS.attr('number'),
-	repliesCount: function() {
-		return Math.max(0, this.get('commentsCount') - 1);
-	}.property('commentsCount'),
+  readTime: DS.attr('date'),
+  readNumber: DS.attr('number'),
+  unreadCount: Ember.computed('lastPostNumber', 'readNumber', 'session.user.readTime', function() {
+    return this.get('session.user.readTime') < this.get('lastTime') ? Math.max(0, this.get('lastPostNumber') - (this.get('readNumber') || 0)) : 0;
+  }),
+  isUnread: Ember.computed.bool('unreadCount'),
 
-	posts: DS.attr('string'),
-	postIds: function() {
-		var posts = this.get('posts') || '';
-		return posts.split(',');
-	}.property('posts'),
-	loadedPosts: DS.hasMany('post'),
-
-	readTime: DS.attr('date'),
-	readNumber: DS.attr('number'),
-	unreadCount: function() {
-		return this.get('lastPostNumber') - this.get('readNumber');
-	}.property('lastPostNumber', 'readNumber'),
-	isUnread: Ember.computed.bool('unreadCount')
+  // Only used to save a new discussion
+  content: DS.attr('string')
 });
-
-export default Discussion;