Add support for the node net module.

frog/samples/node/echoServer.dart

Index: frog/samples/node/echoServer.dart
===================================================================
--- frog/samples/node/echoServer.dart	(revision 0)
+++ frog/samples/node/echoServer.dart	(revision 0)
@@ -0,0 +1,16 @@
+#library('echoServer');
+
+#import('../../lib/node/node.dart');
+#import('../../lib/node/net.dart');
+
+void main() {
+  // Note: the callback function must use the type "Socket" for the socket argument,

[Jennifer Messerly, 2012/01/21 01:00:31]

hmmm. There's some sort of bug here then. You mean Socket.write was not getting
generated in the JS?

if you wouldn't mind it'd be great to file this as an issue on the tracker

+  // otherwise frog will strip out the Socket.write method.
+  var server = net.createServer((Socket socket) {
+    socket.write("Echo server\r\n");
+    socket.pipe(socket);
+  });
+
+  server.listen(1337, "127.0.0.1");
+  print('Listening on port 1337');
+}