Remove library tags, they aren't needed

lib/src/analysis_context.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 dev_compiler.src.analysis_context;
-
 import 'package:analyzer/src/generated/engine.dart';
 import 'package:analyzer/src/generated/java_io.dart' show JavaFile;
 import 'package:analyzer/src/generated/sdk_io.dart' show DirectoryBasedDartSdk;
 import 'package:analyzer/src/generated/source.dart' show DartUriResolver;
 import 'package:analyzer/src/generated/source_io.dart';
 
 import 'dart_sdk.dart';
 import 'multi_package_resolver.dart';
 import 'options.dart';
 
@@ skipping 52 matching lines @@
 DartUriResolver createMockSdkResolver(Map<String, String> mockSources) =>
     new MockDartSdk(mockSources, reportMissing: true).resolver;
 
 /// Creates a [DartUriResolver] that uses the SDK at the given [sdkPath].
 DartUriResolver createSdkPathResolver(String sdkPath) {
   var sdk = new DirectoryBasedDartSdk(
       new JavaFile(sdkPath), /*useDart2jsPaths:*/ true);
   sdk.context.analysisOptions.strongMode = true;
   return new DartUriResolver(sdk);
 }