Rename "pathos" package to "path".

pkg/path/test/dart2js_test.dart

 // Copyright (c) 2013, 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.
 
 import 'package:unittest/unittest.dart';
-import 'package:pathos/path.dart' as path;
+import 'package:path/path.dart' as path;
 
 // In the future, the default root will be window.location.href, but right now
 // that's not possible.
 
 main() {
   group('new Builder()', () {
     test('uses the current working directory if root is omitted', () {
       var builder = new path.Builder();
       expect(builder.root, '.');
     });
 
     test('uses URL if style is omitted', () {
       var builder = new path.Builder();
       expect(builder.style, path.Style.url);
     });
   });
 
   test('current', () {
     expect(path.current, '.');
   });
 }