adding new command-line app tutorial

src/site/docs/tutorials/indexeddb/index.markdown

 ---
 layout: default
 title: "Use IndexedDB"
 description: "Use IndexedDB for persistence and offline capability for your app."
 has-permalinks: true
 tutorial:
   id: indexeddb
-next: 
-next-title: "Home"
+next: cmdline/
+next-title: "Write Command-Line Apps"
 prev: forms/
 prev-title: "Get Input from a Form"
 ---
 
 {% capture whats_the_point %}
 
 * IndexedDB is a new standard for client-side storage in modern web browsers.
 * Client-side storage provides persistence, offline capability,
 and other advantages.
 * IndexedDB lets you store significant amounts of structured data.
@@ skipping 702 matching lines @@
 
 ###What next?
 
 You've completed the tutorials!
 Check out the Dart
 [code samples](/samples/) and [articles](/articles/).
 
 {% endcapture %}
 
 {% include tutorial.html %}