Move internals.dart out of Sky SDK

sky/engine/bindings/builtin_natives.dart

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-library sky_builtin;
+library builtin_natives;
 
 import "dart:async";
 
 // Corelib 'print' implementation.
 void _print(arg) {
   _Logger._printString(arg.toString());
 }
 
 class _Logger {
   static void _printString(String s) native "Logger_PrintString";
@@ skipping 32 matching lines @@
   return new _Timer(milliseconds, callback, repeating);
 }
 
 String _getBaseURLString() native "GetBaseURLString";
 Uri _getBaseURL() => Uri.parse(_getBaseURLString());
 
 _getPrintClosure() => _print;
 _getScheduleMicrotaskClosure() => _scheduleMicrotask;
 _getGetBaseURLClosure() =>_getBaseURL;
 _getCreateTimerClosure() => _createTimer;