Move pub's arg parsing to bin/pub.dart.

sdk/lib/_internal/pub/lib/src/command_version.dart

Index: sdk/lib/_internal/pub/lib/src/command_version.dart
diff --git a/sdk/lib/_internal/pub/lib/src/command_version.dart b/sdk/lib/_internal/pub/lib/src/command_version.dart
index 7c9ad636815ffd8fa9f7e0c387ce450db406abf8..457eebd3f83a1ae79fd868f8d2168bf27909f3e8 100644
--- a/sdk/lib/_internal/pub/lib/src/command_version.dart
+++ b/sdk/lib/_internal/pub/lib/src/command_version.dart
@@ -5,7 +5,10 @@
 library command_version;
 
 import 'dart:async';
-import 'pub.dart';
+
+import 'command.dart';
+import 'log.dart' as log;
+import 'sdk.dart' as sdk;
 
 /// Handles the `version` pub command. 
 class VersionCommand extends PubCommand {
@@ -14,6 +17,6 @@ class VersionCommand extends PubCommand {
   bool get requiresEntrypoint => false;
 
   Future onRun() {
-    printVersion();
+    log.message('Pub ${sdk.version}');
   }
 }