Clean up package imports and library names

pkg/analyzer/lib/src/string_source.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.
 
-library analyzer.string_source;
+library analyzer.src.string_source;
 
-import 'generated/engine.dart' show TimestampedData;
-import 'generated/source.dart';
+import 'package:analyzer/src/generated/engine.dart' show TimestampedData;
+import 'package:analyzer/src/generated/source.dart';
 
 /// An implementation of [Source] that's based on an in-memory Dart string.
 class StringSource extends Source {
   final String _contents;
   final String fullName;
   final int modificationStamp;
 
   StringSource(this._contents, this.fullName)
       : modificationStamp = new DateTime.now().millisecondsSinceEpoch;
 
@@ skipping 22 matching lines @@
       return ssObject._contents == _contents && ssObject.fullName == fullName;
     }
     return false;
   }
 
   bool exists() => true;
 
   Uri resolveRelativeUri(Uri relativeUri) => throw new UnsupportedError(
       "StringSource doesn't support resolveRelative.");
 }