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/public/crossdomain.xml

@@ -0,0 +1,15 @@
+<?xml version="1.0"?>
+<!DOCTYPE cross-domain-policy SYSTEM "http://www.adobe.com/xml/dtds/cross-domain-policy.dtd">
+<cross-domain-policy>
+    <!-- Read this: www.adobe.com/devnet/articles/crossdomain_policy_file_spec.html -->
+
+    <!-- Most restrictive policy: -->
+    <site-control permitted-cross-domain-policies="none"/>
+
+    <!-- Least restrictive policy: -->
+    <!--
+    <site-control permitted-cross-domain-policies="all"/>
+    <allow-access-from domain="*" to-ports="*" secure="false"/>
+    <allow-http-request-headers-from domain="*" headers="*" secure="false"/>
+    -->
+</cross-domain-policy>

framework/core/ember/public/robots.txt

@@ -0,0 +1,2 @@
+# http://www.robotstxt.org
+User-agent: *