Add tools/ddbg_service.

tools/ddbg_service/lib/commando.dart

-// Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
+// Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
+library commando;
+
 import 'dart:async';
 import 'dart:convert';
 import 'dart:io';
 import 'dart:math';
 
-import 'terminfo.dart';
+import 'package:ddbg/terminfo.dart';
 
 typedef List<String> CommandCompleter(List<String> commandParts);
 
 class Commando {
   // Ctrl keys
   static const runeCtrlA   = 0x01;
   static const runeCtrlB   = 0x02;
   static const runeCtrlD   = 0x04;
   static const runeCtrlE   = 0x05;
   static const runeCtrlF   = 0x06;
@@ skipping 464 matching lines @@
     // Write the new text.
     pos = _writeRange(newLine, pos, newLine.length);
 
     // Clear any extra characters at the end.
     pos = _clearRange(pos, _currentLine.length);
 
     // Move the cursor back to the input point.
     _cursorPos = _move(pos, newCursorPos);
     _currentLine = newLine;    
   }
+
+  void print(String text) {
+    bool togglePrompt = _promptShown;
+    if (togglePrompt) {
+      hide();
+    }
+    _stdout.writeln(text);
+    if (togglePrompt) {
+      show();
+    }
+  }
   
   void hide() {
     if (!_promptShown) {
       return;
     }
     _promptShown = false;
     // We need to erase everything, including the prompt.
     var curLine = _getLine(_cursorPos);
     var lastLine = _getLine(_currentLine.length);
 
@@ skipping 175 matching lines @@
   if ('gondola'.startsWith(lastWord)) {
     completions.add('gondola');
   }
 
   return completions;
 }
 
 
 int _helpCount = 0;
 Commando cmdo;
+var cmdoSubscription;
 
 
 void _handleCommand(String rawCommand) {
   String command = rawCommand.trim();
   cmdo.hide();
   if (command == 'quit') {
-    cmdo.close().then((_) {
-        print('Exiting');
-      });
+    var future = cmdoSubscription.cancel();
+    if (future != null) {
+      future.then((_) {
+          print('Exiting');
+          exit(0);
+        });
+    } else {
+      print('Exiting');
+      exit(0);
+    }
   } else if (command == 'help') {
     switch (_helpCount) {
       case 0:
         print('I will not help you.');
         break;
       case 1:
         print('I mean it.');
         break;
       case 2:
         print('Seriously.');
@@ skipping 11 matching lines @@
   } else {
     print('Received command($command)');
   }
   cmdo.show();
 }
 
 
 void main() {
   print('[Commando demo]');
   cmdo = new Commando(completer:_myCompleter);
-  cmdo.commands.listen(_handleCommand);
+  cmdoSubscription = cmdo.commands.listen(_handleCommand);
 }