Clean up package imports and library names

pkg/analyzer/test/src/task/strong_mode_test.dart

 // Copyright (c) 2015, 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.
 
-library test.src.task.strong_mode_test;
+library analyzer.test.src.task.strong_mode_test;
 
 import 'package:analyzer/src/generated/ast.dart';
 import 'package:analyzer/src/generated/element.dart';
 import 'package:analyzer/src/generated/source.dart';
 import 'package:analyzer/src/task/strong_mode.dart';
 import 'package:unittest/unittest.dart';
 
 import '../../reflective_tests.dart';
 import '../../utils.dart';
 import '../context/abstract_context.dart';
@@ skipping 1024 matching lines @@
     }
   }
 }
 ''');
     CompilationUnit unit = context.resolveCompilationUnit2(source, source);
     VariableGatherer gatherer = new VariableGatherer(filter);
     unit.accept(gatherer);
     return gatherer.results;
   }
 }