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/discussion/post-comment.js

@@ -0,0 +1,107 @@
+import Ember from 'ember';
+
+import UseComposer from 'flarum/mixins/use-composer';
+import FadeIn from 'flarum/mixins/fade-in';
+import HasItemLists from 'flarum/mixins/has-item-lists';
+import ComposerEdit from 'flarum/components/composer/composer-edit';
+import PostHeaderUser from 'flarum/components/discussion/post-header/user';
+import PostHeaderMeta from 'flarum/components/discussion/post-header/meta';
+import PostHeaderEdited from 'flarum/components/discussion/post-header/edited';
+import PostHeaderToggle from 'flarum/components/discussion/post-header/toggle';
+
+var precompileTemplate = Ember.Handlebars.compile;
+
+/**
+  Component for a `comment`-typed post. Displays a number of item lists
+  (controls, header, and footer) surrounding the post's HTML content. Allows
+  the post to be edited with the composer, hidden, or restored.
+ */
+export default Ember.Component.extend(FadeIn, HasItemLists, UseComposer, {
+  layoutName: 'components/discussion/post-comment',
+  tagName: 'article',
+  classNames: ['post', 'post-comment'],
+  classNameBindings: [
+    'post.isHidden:deleted',
+    'post.isEdited:edited',
+    'revealContent:reveal-content'
+  ],
+  itemLists: ['controls', 'header', 'footer'],
+
+  // The stream-content component instansiates this component and sets the
+  // `content` property to the content of the item in the post-stream object.
+  // This happens to be our post model!
+  post: Ember.computed.alias('content'),
+
+  populateControls: function(items) {
+    if (this.get('post.isHidden')) {
+      this.addActionItem(items, 'restore', 'Restore', 'reply', 'post.canEdit');
+      this.addActionItem(items, 'delete', 'Delete', 'times', 'post.canDelete');
+    } else {
+      this.addActionItem(items, 'edit', 'Edit', 'pencil', 'post.canEdit');
+      this.addActionItem(items, 'hide', 'Delete', 'times', 'post.canEdit');
+    }
+  },
+
+  // Since we statically populated controls based on the value of
+  // `post.isHidden`, we'll need to refresh them every time that property
+  // changes.
+  refreshControls: Ember.observer('post.isHidden', function() {
+    this.initItemList('controls');
+  }),
+
+  populateHeader: function(items) {
+    var properties = this.getProperties('post');
+    items.pushObjectWithTag(PostHeaderUser.create(properties), 'user');
+    items.pushObjectWithTag(PostHeaderMeta.create(properties), 'meta');
+    items.pushObjectWithTag(PostHeaderEdited.create(properties), 'edited');
+    items.pushObjectWithTag(PostHeaderToggle.create(properties, {parent: this}), 'toggle');
+  },
+
+  savePost: function(post, data) {
+    post.setProperties(data);
+    return this.saveAndDismissComposer(post);
+  },
+
+  actions: {
+    // In the template, we render the "controls" dropdown with the contents of
+    // the `renderControls` property. This way, when a post is initially
+    // rendered, it doesn't have to go to the trouble of rendering the
+    // controls right away, which speeds things up. When the dropdown button
+    // is clicked, this will fill in the actual controls.
+    renderControls: function() {
+      this.set('renderControls', this.get('controls'));
+    },
+
+    edit: function() {
+      var post = this.get('post');
+      var component = this;
+      this.showComposer(function() {
+        return ComposerEdit.create({
+          user: post.get('user'),
+          post: post,
+          submit: function(data) { component.savePost(post, data); }
+        });
+      });
+    },
+
+    hide: function() {
+      var post = this.get('post');
+      post.setProperties({
+        isHidden: true,
+        deleteTime: new Date,
+        deleteUser: this.get('session.user')
+      });
+      post.save();
+    },
+
+    restore: function() {
+      var post = this.get('post');
+      post.setProperties({
+        isHidden: false,
+        deleteTime: null,
+        deleteUser: null
+      });
+      post.save();
+    }
+  }
+});