Backbone: Update Backbone, jQuery
Backbone: Reset input on revert

Fix #896, using solution by @shaci
AngularJS: Upgrade to 1.2.16
Upgrade Knockout to v3.1.0
Update Twitter card tags for homepage

According to https://dev.twitter.com/docs/cards/types/summary-card
Add site twitter cards tag

https://dev.twitter.com/docs/cards/getting-started
React: Upgrade to 0.10
React+Bower: Upgrade to React 0.10
Upgrade blog URL
learn: Add link to React flux example
Learn: Update AngularJS videos link
Ember: Upgrade to 1.5.1
Remove Backbone.xmpp

fixes #446
fixes #474

It's offline and not maintained anymore.
AngularJS: Remove unnecessary ng-controller

Fix #898

The router already takes care of initializing the controller, doing it again in
the markup causes the initialization to happen twice. Thanks @ruffle1986 for
reporting.