Add mojo package manager skeleton.

mojo/tools/package_manager/package_manager.cc

Index: mojo/tools/package_manager/package_manager.cc
diff --git a/mojo/apps/js/main.cc b/mojo/tools/package_manager/package_manager.cc
similarity index 62%
copy from mojo/apps/js/main.cc
copy to mojo/tools/package_manager/package_manager.cc
index 5ecf47d5d061ffb049f35c4d7a2df9ab3e1a2bb3..b091f6d5ddea08462bc13c5cd6b2f4ac41f65cc1 100644
--- a/mojo/apps/js/main.cc
+++ b/mojo/tools/package_manager/package_manager.cc
@@ -2,14 +2,11 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#include "base/i18n/icu_util.h"
 #include "mojo/application/application_runner_chromium.h"
-#include "mojo/apps/js/application_delegate_impl.h"
 #include "mojo/public/c/system/main.h"
+#include "mojo/tools/package_manager/package_manager_application.h"
 
 MojoResult MojoMain(MojoHandle shell_handle) {
-  base::i18n::InitializeICU();
-  mojo::ApplicationRunnerChromium runner(
-      new mojo::apps::ApplicationDelegateImpl());
+  mojo::ApplicationRunnerChromium runner(new mojo::PackageManagerApplication);
   return runner.Run(shell_handle);
 }