edit pass on T3,4,5, updated images

src/site/docs/tutorials/shared-pkgs/index.markdown

 ---
 layout: default
 title: "Install Shared Packages"
 description: "Packages are bundles of source code, tools, and resources that help you to organize and share code"
 has-permalinks: true
 tutorial:
   id: packages
 next: polymer-intro/
 next-title: "Define a Custom Element"
 prev: remove-elements/
@@ skipping 30 matching lines @@
 </div>
 
 Now that you're able to create and run a Dart application
 and have a basic understanding of DOM programming,
 you are ready to leverage code written by other programmers.
 Many interesting and useful packages of reusable Dart code
 are available at the
 <a href="https://pub.dartlang.org/">pub.dartlang.org</a>
 repository.
 
-This target shows you how to use `pub`&mdash;a package manager
+This tutorial shows you how to use `pub`&mdash;a package manager
 that comes with Dart&mdash;to
 install one of the packages in the repository,
 the vector_math package.
 You can follow these same steps to install any package hosted at
 <a href="https://pub.dartlang.org/">pub.dartlang.org</a>;
 just change the package name when you get to that step.
-This target also describes some of the resources you can expect to find
+This tutorial also describes some of the resources you can expect to find
 in a well-built package.
 
 * [About the pubspec.yaml file](#about-pubspec)
 * [Name the package dependencies](#name-dependencies)
 * [Install the package dependencies](#install-dependencies)
 * [What did you get (and not get)?](#about-packages)
 * [Import libraries from a package](#use-package)
 * [Other resources](#other-resources)
+* [What next?](#what-next)
 
 ##About the pubspec.yaml file {#about-pubspec}
 
 To use an external package,
 your application must itself be a package.
 Any application with a valid pubspec.yaml file in its top-level directory
 is a package and can therefore use external packages.
 When you create an application using Dart Editor,
 Dart Editor automatically creates a `pubspec.yaml` file.
 
 Start Dart Editor and create a new application with the name `vector_victor`.
 Double click pubspec.yaml to view its contents.
 
 ![Dart Editor with pubspec.yaml file](images/victor-files.png)
 
 The pubspec.yaml file contains the package specification written in YAML
 (visit <a href="https://pub.dartlang.org/doc/pubspec.html">Pubspec Format</a>
 for in-depth coverage).
 Dart Editor provides a user interface for editing the pubspec.yaml file
 so that you don't have to worry about the YAML format.
 Or you can click the **Source** tab at the bottom of the Editor pane
 to edit the YAML code directly.
 Below is the pubspec.yaml file that was
 created for the vector_victor application.
 
 ![The default pubspec.yaml file specifies name and description](images/pubspec.png)
 
 The package name is required.
-All web applications are dependent on the browser package
-provided at pub.dartlang.org.
+You'll note that the pubspec.yaml file already
+lists a dependency on the browser package.
+Web applications that don't use Polymer
+need the browser package.
 
 {% comment %}
 ##...Or put an existing application into a package {#old-app-in-pkg}
 
 If you already have an application
 and want it to use an external package,
 simply create a pubspec.yaml file in the application's top-level directory.
 Your pubspec.yaml file must at least specify the package name.
 
 ![The smallest possible pubspec.yaml](images/minimalpubspec.png)
@@ skipping 18 matching lines @@
 you need to add the package to your
 application's list of _dependencies_
 in the pubspec.yaml file.
 Each item in the dependencies list
 specifies the name, and sometimes the version,
 of a package that your application uses.
 
 Let's make the vector_victor application have a dependency 
 on the vector_math package,
 which is available at pub.dartlang.org.
-Click the **Add** button in Dart Editor.
+
+* Click the **Add** button in Dart Editor.
 
 ![Click the add button to add a package dependency](images/dependencies-ui.png)
 
-Enter the name of the package in the popup window.
+* Enter the name of the package in the popup window.
 
 ![Enter the package name](images/add-dependency-window.png)
 
 Dart Editor adds the package name to the list.
 
 ![The application is now dependent on vector_math](images/after-add.png)
 
 Notice the **Version** field.
 `any` means that this application can use
 any version of the vector_math package.
@@ skipping 108 matching lines @@
   </div>
   <hr>
 </div>
 
 ##Import libraries from a package {#use-package}
 
 Open the vector_math directory by clicking the little arrow.
 
 ![Finally, the vector_math library files](images/the-vectormath-library.png)
 
-The directory contains a Dart file,
+The directory contains a Dart file called vector_math.dart,
 which you import into your Dart application,
 and a `src` directory,
-which contains all of the source code for the library.
+which contains the source code for the library.
 As with the SDK libraries,
 use the import directive to use code from an installed library.
 The Dart SDK libraries are built-in and
 are identified with the special dart: prefix.
 For external libraries installed by pub,
 use the `package:` prefix.
 
 {% prettify dart %}
 import 'package:vector_math/vector_math.dart';
 {% endprettify %}
 
 Note that you specify the filename, not the library name.
 
 ##Other resources
 
 <ul>
   <li>
     Dart developers share packages at
     <a href="https://pub.dartlang.org/">pub.dartlang.org</a>.
     Look there for packages that might be useful to you,
     or share your own Dart packages.
     See the <a href="https://pub.dartlang.org/doc/">pub documentation</a>
     to get started using and sharing packages.
   </li>
-  <li>
-    One important package that you will find there
-    is
-    <a href="https://pub.dartlang.org/packages/web_ui">web_ui</a>&mdash;a package
-    created by the Dart team that lets you use Web components and templating.
-    The
-    <a href="/docs/tutorials/web-ui/">next target</a> covers Web UI.
-  </li>
 </ul>
 
+##What next? {#what-next}
+
+One package at pub.dartlang.org is Polymer.dart,
+which makes writing web applications easier
+with data binding, templates, and declarative event handlers.
+Check out the next tutorial,
+[Define a Custom Element](/docs/tutorials/polymer-intro),
+for an introduction to Polymer.
+
+
 {% endcapture %}
 
 {% include tutorial.html %}