Move sky_home.* from domokit.github.io into our repo

This makes it easier to keep sky_home links working.

R=abarth@chromium.org

Review URL: https://codereview.chromium.org/1185473002.

sky_home

+#!mojo mojo:sky_viewer
+<sky>
+<script>
+import 'sky_home.dart';
+
+void main() {
+  new SkyHome();
+}
+</script>
+</sky>

sky_home.dart

+import 'dart:sky';
+import 'package:sky/framework/fn.dart';
+import 'package:sky/framework/components/button.dart';
+import 'package:sky/framework/components/scaffold.dart';
+import 'package:sky/framework/components/tool_bar.dart';
+import 'package:sky/framework/theme/colors.dart';
+import 'package:sky/framework/theme/typography.dart' as typography;
+
+class SkyLink extends Component {
+  String text;
+  String href;
+
+  SkyLink(String text, this.href) : this.text = text, super(key: text);
+
+  UINode build() {
+    return new EventListenerNode(
+      new Button(key: text, content: new Text(text), level: 1),
+      onPointerUp: (_) => window.location.href = href
+    );
+  }
+}
+
+class SkyHome extends App {
+  static final Style _actionBarStyle = new Style('''
+    background-color: ${Green[500]};''');
+
+  static final Style _titleStyle = new Style('''
+    ${typography.white.title};''');
+
+  UINode build() {
+    List<UINode> children = [
+      new SkyLink('Stocks2 App', '/examples/stocks2/lib/stock_app.dart'),
+      new SkyLink('Interactive Flex', '/examples/raw/interactive_flex.dart'),
+      new SkyLink('Ink Well', '/examples/raw/ink_well.dart'),
+      new SkyLink('Box2D Game', '/examples/game/main.dart'),
+      new SkyLink('Sector Layout', '/examples/raw/sector_layout.dart'),
+
+      // TODO(eseidel): We could use to separate these groups?
+      new SkyLink('Stocks App (Old)', '/examples/stocks/main.sky'),
+      new SkyLink('Touch Demo (Old)', '/examples/raw/touch-demo.sky'),
+      new SkyLink('Spinning Square (Old)', '/examples/raw/spinning-square.sky'),
+
+      new SkyLink('Licences (Old)', '/LICENSES.sky'),
+    ];
+
+    return new Scaffold(
+      // FIXME: ActionBar should have a better default style than transparent.
+      header: new StyleNode(
+        // FIXME: left should be optional, but currently crashes when null.
+        new ToolBar(left: new Text(''),
+          center: new Container(children: [new Text('Sky Demos')], style: _titleStyle)),
+        _actionBarStyle),
+      content: new Container(children: children)
+    );
+  }
+}
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