Remove DirectoryException and LinkException from dart:io and use FileException instaed.

tests/standalone/io/link_test.dart

Index: tests/standalone/io/link_test.dart
diff --git a/tests/standalone/io/link_test.dart b/tests/standalone/io/link_test.dart
index ddcb0ee7e828ffb027fde4b7bb83f1353349ad6b..ff9f70f7493c4e705cb57428ec87a43b3f03766e 100644
--- a/tests/standalone/io/link_test.dart
+++ b/tests/standalone/io/link_test.dart
@@ -204,7 +204,7 @@ void testLinkErrorSync() {
   Expect.throws(() =>
       new Link('some-dir-that-doent exist/some link file/bla/fisk').createSync(
           'bla bla bla/b lalal/blfir/sdfred/es'),
-      (e) => e is LinkException);
+      (e) => e is FileSystemException);
 }
 
 checkExists(String filePath) => Expect.isTrue(new File(filePath).existsSync());