pkg: analysis aided cleanup

Removed a lot of warnings and hints when opening many pkg projects in the editor

R=gram@google.com

Review URL: https://codereview.chromium.org//22284003

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge/dart/pkg/yaml@25831 260f80e4-7a28-3924-810f-c04153c831b5
diff --git a/pkgs/yaml/lib/src/model.dart b/pkgs/yaml/lib/src/model.dart
index d7ee481..37247f0 100644
--- a/pkgs/yaml/lib/src/model.dart
+++ b/pkgs/yaml/lib/src/model.dart
@@ -7,7 +7,6 @@
 /// representation graph.
 library model;
 
-import 'model.dart';
 import 'parser.dart';
 import 'utils.dart';
 import 'visitor.dart';