title: rubyzip Zip::FileSystem::ZipFsDir glob method broken?
body: <p>Using version 1.2.0, I am getting strange results when I try to call <code>glob</code> on a <code>ZipFsDir</code> object.  In a rails console:</p>
  
  <pre><code>&gt; require 'zip/filesystem'
   =&gt; true 
  &gt; file = '/home/me/test.zip'
   =&gt; "/home/me/test.zip" 
  &gt; zf = Zip::File.open file
   =&gt; #&lt;Zip::File:0x0000000880e0c8...
  &gt; d = zf.dir
   =&gt; #&lt;Zip::FileSystem::ZipFsDir:0x0000000880e028
  &gt; d.class
   =&gt; Zip::FileSystem::ZipFsDir
  &gt; d.glob("*.shp")
  NoMethodError: undefined method `glob' for #&lt;Zip::FileSystem::ZipFileNameMapper:0x0000000880e078&gt;
  </code></pre>
  
  <p>Why is it reporting that the method is undefined for <code>Zip::FileSystem::ZipFileNameMapper</code>? I called it on a <code>ZipFsDir</code> object. The docs clearly list <code>glob</code> as a <a href="http://www.rubydoc.info/gems/rubyzip/1.2.0/Zip/FileSystem/ZipFsDir#glob-instance_method" rel="nofollow">ZipFsDir instance method</a>.</p>