update (Atma.js) rewrite the app

Add riot.js 2.0 example

DUEL: App Update (#1110), cancel editing on escape keypress (#789), and routing support (#812)

Update AngularJS case studies links

Replace deprecated Controller

Remove cloud9 and Codio links in the readme

Fix #1428
Fix #957

Also updates TodoMVC style/structure to latest.

Changing redraw strategy while handling input events

The app has been down for multiple years, was left unmaintained for
really long and is outdated in many ways. Thus, we're (temporarily)
removing it. If somebody comes in, volunteers to fix the problems and we
find a place to host it.

We already decided earlier to drop it from the homepage.
Ref 7f59ef71

Fixes gh-546
Fixes gh-593

Update readme to include a note about unminified libs

Fix #378

Some CSS in todomvc-app-css has to be replicated in the example itself
as some selectors have to differ. This updates it to the last version.

Fix #1418

issues.

Fix style issues: missing spaces.

Fix avoid double deletion when handling empty input and the following blur event.

Update backbone to 2.0

As the author doesn't respond anymore and the framework hasn't been
updated for really long.

Ref gh-1209

* backbone
* jquery
* underscore
* todomvc common js

fix: Finish renaming stopEditing to saveEditing

Fix #1409

Fix #1410

Do not show number of items completed in the Clear completed button.