docs(quickstart): post-RC5 Dart resync

- Resync Dart QS prose with TS, post RC5.
- Delete cached QS jade file.
- Eliminate the stub file `styles.1.css` in favor of a `docregion` in
the main `styles.css`.

This commit requires a `gulp add-example-boilerplate`.
Contributes to angular#2077.

Author: chalin

public/docs/_examples/quickstart/dart/web/styles_1.css

@@ -1,3 +1,4 @@
+/* #docregion , quickstart */
 /* Master Styles */
 h1 {
   color: #369;
@@ -12,6 +13,7 @@ h2, h3 {
 body {
   margin: 2em;
 }
+/* #enddocregion quickstart */
 body, input[text], button {
   color: #888;
   font-family: Cambria, Georgia;

public/docs/_examples/quickstart/ts/styles.1.css

@@ -1,11 +1,16 @@
-extends ../../ts/_cache/quickstart.jade
+extends ../../ts/latest/quickstart.jade
 
 block includes
   include _util-fns
   - var _Install = 'Get'
   - var _prereq = 'the Dart SDK'
-  - var _angular_browser_uri = 'package:angular2/platform/browser.dart'
-  - var _angular_core_uri = 'package:angular2/core.dart'
+  - var _angular_browser_uri = 'angular2/platform/browser.dart'
+  - var _angular_core_uri = 'angular2/core.dart'
+  - var _stepInit = 3
+  - var _quickstartSrcURL='https://github.com/angular-examples/quickstart'
+  - var _AppModuleVsRootComp = 'AppComponent'
+  - var _moduleVsComp = 'component'
+  - var _platformBrowserDynamic = 'bootstrap'
 
 block setup-tooling
   :marked
@@ -20,9 +25,6 @@ block setup-tooling
     [DT]: https://www.dartlang.org/tools/
     [pub]: https://www.dartlang.org/tools/pub/
 
-block download-source
-  // exclude this section from Dart
-
 block package-and-config-files
   :marked
     In the project folder just created, create a file named
@@ -59,9 +61,6 @@ block create-main
     li a #[b folder named #[code web]]
     li a <b>file named #[code #[+adjExPath('app/main.ts')]]</b> with the following content:
 
-block index-html-commentary-for-ts
-  //- N/A
-
 block run-app
   p.
     We have a few options for running our app.
@@ -87,22 +86,23 @@ block build-app
       in the [proper folders](#wrap-up),
       and run `pub get`.
 
-  .l-verbose-section
-    h3#section-angular-run-app Building the app (generating JavaScript)
-
+  .l-verbose-section#section-angular-run-app
     :marked
+      ### Building the app (generating JavaScript)
+
       Before deploying the app, we need to generate JavaScript files.
       The `pub build` command makes that easy.
 
     code-example(language="sh").
       &gt; <span class="blk">pub build</span>
       Loading source assets...
 
-    p.
+    :marked
       The generated JavaScript appears, along with supporting files,
-      under a directory named <code>build</code>.
+      under a directory named `build`.
 
-    h4#angular_transformer Using the Angular transformer
+    #angular_transformer
+    h4 Using the Angular transformer
 
     p.
       When generating JavaScript for an Angular app,
@@ -124,7 +124,7 @@ block build-app
       <a href="https://github.com/angular/angular/wiki/Angular-2-Dart-Transformer">Angular
       transformer wiki page</a>.
 
-    #performance.l-sub-section
+    .l-sub-section#performance
       h3 Performance, the transformer, and Angular 2 libraries
       p.
         When an app imports <code>bootstrap.dart</code>,
@@ -136,7 +136,8 @@ block build-app
         (<code>entry_points</code> in <code>pubspec.yaml</code>)
         so that they don't use mirrors.
 
-    h4#dart_to_js_script_rewriter Using dart_to_js_script_rewriter
+    #dart_to_js_script_rewriter
+    h4 Using dart_to_js_script_rewriter
 
     :marked
       To improve the app's performance, convert the
@@ -203,6 +204,3 @@ block project-files
     index.html,
     pubspec.yaml,
     styles.css`)
-
-block what-next-ts-overhead
-  //- N/A