Extend dart:io error handling to all socket functions

tests/standalone/src/io/SocketStreamCloseTest.dart

 // Copyright (c) 2012, 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.
 //
 // VMOptions=
 // VMOptions=--short_socket_read
 // VMOptions=--short_socket_write
 // VMOptions=--short_socket_read --short_socket_write
 //
 // Test socket close events.
@@ skipping 282 matching lines @@
             Expect.fail("Unknown test mode");
         }
       }
 
       void closeHandler() {
         _closeEvents++;
         connection.outputStream.close();
       }
 
       void errorHandler(Exception e) {
-        Expect.fail("Socket error");
+        Expect.fail("Socket error $e");
       }
 
       _iterations++;
 
       connection.inputStream.onData = dataHandler;
       connection.inputStream.onClosed = closeHandler;
       connection.onError = errorHandler;
     }
 
     void errorHandlerServer(Exception e) {
@@ skipping 93 matching lines @@
   var tests = 9;
   var port = new ReceivePort();
   var completed = 0;
   port.receive((message, ignore) {
     if (++completed == tests) port.close();
   });
   for (var i = 0; i < tests; i++) {
     new SocketClose.start(i, port.toSendPort());
   }
 }