A few small changes to the "pub lish" confirmation UI.

* Don't collapse the root directory of a directory tree, since this is usually
  going to be a very heterogeneous set of files and directories.

* Indent "(N more...)" two fewer spaces. This makes it clearer at what level
  things are collapsed when it comes immediately after a directory. E.g.

      |-- dir
      |   '-- file
      | (6 more...)
      |-- other-dir

  vs

      |-- dir
      |   '-- file
      |   (6 more...)
      |-- other-dir

Review URL: https://codereview.chromium.org//11442068

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge@16085 260f80e4-7a28-3924-810f-c04153c831b5