Update polymer tutorial; make directory paths match new sample structure

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

 ---
 layout: tutorial
 title: "Write Command-Line Apps"
 description: "Basics for command-line apps"
 has-permalinks: true
 tutorial:
   id: dart-io
 next: httpserver
 next-title: "Write HTTP Clients & Servers"
 prev: indexeddb/
 prev-title: "Use IndexedDB"
 ---
 
 {% capture whats_the_point %}
 
 * Command-line applications need to do input and output.
 * The dart:io library provides I/O functionality.
 * The args package helps define and parse command-line arguments.
 * Most input and output requires the use of Streams.
 * Streams provide a series of asynchronous data events.
 * To handle asynchronous data, you need to use Futures.
 
 {% endcapture %}
 
 {% capture sample_links %}
 
-<p> This tutorial features these examples:</p>
-* helloworld
-* dcat
+This tutorial features the following example
+under the **cmdline/bin** directory:
+
+* dcat.dart
 
 <p>
 Don't have the source code?
 <a href="https://github.com/dart-lang/dart-tutorials-samples/archive/master.zip">
   Download it.
 </a>
 
 {% endcapture %}
 
 {% capture content %}
@@ skipping 157 matching lines @@
 | <a href="https://api.dartlang.org/args/ArgParser" target="_blank">ArgParser</a> | A class that parses command-line arguments |
 | <a href="https://api.dartlang.org/args/ArgResults" target="_blank">ArgResults</a> | The result of parsing command-line arguments using ArgParser. |
 {: .table }
 
 Let's take a look at the `dcat` sample,
 which uses ArgParser and ArgResults to parse and store its command-line arguments.
 
 <ol>
 <li markdown="1">
 Copy the sample file from the github repo:
-<a href="https://github.com/dart-lang/dart-tutorials-samples/blob/master/bin/cmdline/dcat.dart">dcat.dart</a>.
+<a href="https://github.com/dart-lang/dart-tutorials-samples/blob/master/cmdline/bin/dcat.dart">dcat.dart</a>.
 </li>
 
 <li markdown="1">
-Run the program from the command line as shown by the highlighted text.
+Run the program from the command line as shown by the **boldface** text.
 
-{% prettify bash %}
-$ [[highlight]]dart dcat.dart -n quotes.txt[[/highlight]]
+<pre>
+$ <b>dart dcat.dart -n quotes.txt</b>
 1 Be yourself. Everyone else is taken. -Oscar Wilde
 2 Don't cry because it's over, smile because it happened. -Dr. Seuss
 3 You only live once, but if you do it right, once is enough. -Mae West
 ...
-{% endprettify %}
+</pre>
 
 The program displays the contents of the source code file and
 preceeds each line with a line number.
 </li>
 
 </ol>
 
 The following diagram shows how the `dcat` command line used above
 is parsed into the `ArgResults` object.
 
 ![ArgsParser parses command-line arguments](images/commandlineargs.png)
 
 You can access flags and options by name,
 treating the ArgResults object like a Map.
 You can access other values with properties such as `rest`.
 
 Here's the code from `dcat` that deals with command-line arguments:
 
 <pre class="prettyprint lang-dart">
-
 ...
 <a href="#" class="dart-popover" data-toggle="popover" title="Parsed arguments" data-html="true" data-trigger="hover focus" data-content="This object contains parsed options and flags.">ArgResults argResults;</a>
 
 void main(<a href="#" class="dart-popover" data-toggle="popover" title="Command-line arguments" data-html="true" data-trigger="hover focus" data-content="The system passes command-line arguments into the program in a list of strings.">List&lt;String&gt; arguments</a>) {
   final parser = new ArgParser()
       <a href="#" class="dart-popover" data-toggle="popover" title="Define a valid flag" data-html="true" data-trigger="hover focus" data-content="Add a flag definition to the command-line argument parser. This code defines the flag -n, which when used displays line numbers.">..addFlag(LINE_NUMBER, negatable: false, abbr: 'n')</a>;
 
   argResults = parser.<a href="#" class="dart-popover" data-toggle="popover" title="Parse the arguments" data-html="true" data-trigger="hover focus" data-content="Parse the arguments that were passed into the main() function. The parser stops parsing if it finds an undefined option or flag.">parse(arguments)</a>;
   List&lt;String&gt; paths = <a href="#" class="dart-popover" data-toggle="popover" title="Remaining arguments" data-html="true" data-trigger="hover focus" data-content="To get the arguments that remain after parsing all of the valid options and flags, use the rest property.">argResults.rest</a>;
 
@@ skipping 385 matching lines @@
 [Write HTTP Clients & Servers](/docs/tutorials/httpserver/).
 
 * The [Get Input from a Form](/docs/tutorials/forms/) tutorial
 features a client-server.
 The code for the server, which uses CORS headers and handles
 POST requests, is explained in detail.
 
 {% endcapture %}
 
 {% include tutorial.html %}