removing Web UI tutorials, updating remaining 4 to current release, + review pass

src/site/articles/web-ui/index.markdown

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 layout: default
 title: "Web UI Package"
 rel:
   author: sigmund-cherem
 description: "Use web components and templates today with Dart. This brief
      introduction shows you how to use the features of tomorrow, today."
 has-permalinks: true
 ---
 {% comment %}
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 and cool ideas have been proposed, such as [model-driven views][mdv] (MDV).
 
 Web UI combines the ideas from web components and MDV, adapting them to work
 well with Dart.  The package takes advantage of advanced browser features when
 possible, emulating missing features when necessary.
 
 This article walks through some examples. For more details, check out our
 [specification](spec.html), the [summary of features](summary.html), and our
 [installation instructions](tools.html).
 
-<aside class="alert alert-info">
-<strong>Try our tutorials!</strong>
-For a gentle introduction to using Web UI, see the tutorials in
-<a href="/docs/tutorials/">A Game of Darts</a>.
-Web UI coverage starts in
-<a href="/docs/tutorials/web-ui/">Target 6: Get Started with Web UI</a>.
-</aside>
-
 <aside class="alert alert-danger">
 <strong>Note:</strong> The examples in this article do not work
 out of the box in a standard Dart SDK;
 you first need to set up the Dart Web UI tools.
 See the page <a href="tools.html">Tools for Web UI</a>
 for details on using Dart Editor and command-line scripts
 to compile code that uses Web UI.
 </aside>
 
 {% include toc.html %}
@@ skipping 510 matching lines @@
 [project]: https://github.com/dart-lang/web-ui/
 [bugs]: https://github.com/dart-lang/web-ui/issues
 [backbone]: http://backbonejs.org/
 [angular]: http://angularjs.org/
 [ember]: http://emberjs.com/
 [todomvcindwc]: https://github.com/dart-lang/web-ui/tree/master/example/todomvc
 [watcher]: http://dart-lang.github.com/web-ui/docs/watcher.html
 [watcher.dispatch]: http://dart-lang.github.com/web-ui/docs/watcher.html#dispatch
 [group]: https://groups.google.com/a/dartlang.org/group/web-ui/topics
 [so]: http://stackoverflow.com/tags/dart