Make directory action work with Ruby 2.0

Since https://github.com/ruby/ruby/commit/f65e683ccc3b6689ac00e7c1fe0fd2c0384824b2 dot files are only listed when using `FNM_DOTMATCH`.

There are a lot of failing tests with Ruby 2.0 but the most part are related with some `FileUtils` methods becoming private for same reason that I could not find