Added new server/cmdline/io programmers' guide.

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

 ---
-layout: default
+layout: tutorial
 title: "Fetch Data Dynamically"
 description: "Use HttpRequest to fetch data from a file or a server."
 has-permalinks: true
 tutorial:
   id: fetchdata
 next: forms/
 next-title: "Get Input from a Form"
 prev: streams/
 prev-title: "Use Streams for Data"
 ---
@@ skipping 464 matching lines @@
 * The next tutorial,
 [Get Input from a Form](/docs/tutorials/forms/),
 contains a client/server example that
 shows you how to use a form to get data from the user,
 and using JSON, send that form to a server,
 and handle the server's response.
 
 {% endcapture %}
 
 {% include tutorial.html %}