Correct handling of parameters passed to main.

pkg/polymer/bin/new_entry.dart

 ///
 /// Script to create boilerplate for a Polymer element.
 /// Produces new .html entry point for a polymer app and updates the
 /// pubspec.yaml to reflect it.
 ///
 /// Run this script with pub run:
 ///
 ///     pub run polymer:new_entry <html_file>
 ///
 import 'dart:io';
 import 'package:args/args.dart';
 import 'package:path/path.dart' as path;
 import 'package:yaml/yaml.dart';
 import 'package:source_span/source_span.dart';
 
 void printUsage() {
   print('pub run polymer:new_entry entry_point_file.html');
 }
 
 void main(List<String> args) {
   var parser = new ArgParser(allowTrailingOptions: true);
   parser.addFlag('help', abbr: 'h');
   var entryPoint;
 
   try {
     var options = parser.parse(args);
-    if (options['help'] != null) {
+    if (options['help']) {
       printUsage();
       return;
     }
     entryPoint = options.rest[0];
   } catch(e) {
     print('$e\n');
     printUsage();
     exitCode = 1;
     return;
   }
@@ skipping 141 matching lines @@
         '${textToInsert}\n${pubspecText.substring(insertionPoint)}';
   }
 
   _writePubspec(pubspecPath, pubspecText);
   return true;
 }
 
 _writePubspec(String pubspecPath, String text) {
   new File(pubspecPath).writeAsStringSync(text);
 }