Support subcommands in pub and pub help.

sdk/lib/_internal/pub/lib/src/command/lish.dart

Index: sdk/lib/_internal/pub/lib/src/command/lish.dart
diff --git a/sdk/lib/_internal/pub/lib/src/command/lish.dart b/sdk/lib/_internal/pub/lib/src/command/lish.dart
index bd9c445ef4d67012bfb9b215e78283c0bf205a50..d5e46763ecf3ad6641924a86a9c0c79be768390e 100644
--- a/sdk/lib/_internal/pub/lib/src/command/lish.dart
+++ b/sdk/lib/_internal/pub/lib/src/command/lish.dart
@@ -10,7 +10,6 @@ import 'package:http/http.dart' as http;
 
 import '../command.dart';
 import '../directory_tree.dart';
-import '../exit_codes.dart' as exit_codes;
 import '../http.dart';
 import '../io.dart';
 import '../log.dart' as log;
@@ -94,9 +93,7 @@ class LishCommand extends PubCommand {
 
   Future onRun() {
     if (force && dryRun) {
-      log.error('Cannot use both --force and --dry-run.');
-      this.printUsage();
-      return flushThenExit(exit_codes.USAGE);
+      usageError('Cannot use both --force and --dry-run.');
     }
 
     var packageBytesFuture = entrypoint.packageFiles().then((files) {
@@ -144,15 +141,15 @@ class LishCommand extends PubCommand {
 
       if (dryRun) {
         var s = warnings.length == 1 ? '' : 's';
-        log.warning("Package has ${warnings.length} warning$s.");
+        log.warning("\nPackage has ${warnings.length} warning$s.");
         return false;
       }
 
-      var message = 'Looks great! Are you ready to upload your package';
+      var message = '\nLooks great! Are you ready to upload your package';
 
       if (!warnings.isEmpty) {
         var s = warnings.length == 1 ? '' : 's';
-        message = "Package has ${warnings.length} warning$s. Upload anyway";
+        message = "\nPackage has ${warnings.length} warning$s. Upload anyway";
       }
 
       return confirm(message).then((confirmed) {