title: Sass issue when i use the --watch parameter
body: <p>When i execute the line </p>
  
  <pre><code>$sass --watch sass/views.scss:views.css
  </code></pre>
  
  <p>i get the following message</p>
  
  <blockquote>
    <blockquote>
      <blockquote>
        <p>Sass is watching for changes. Press Ctrl-C to stop.
        NameError: uninitialized constant Listen::MultiListener
        Use --trace for backtrace.</p>
      </blockquote>
    </blockquote>
  </blockquote>
  
  <p>As you can say the process stops immediately and the watch option doesn't work.</p>
  
  <p>What's the problem here ?? I have installed the Ruby 2.0.0-p0 version.</p>
  
  <p>Any help appreciated.</p>
  
  <p><strong>EDIT:</strong> (--trace)</p>
  
  <blockquote>
    <blockquote>
      <blockquote>
        <p>Sass is watching for changes. Press Ctrl-C to stop.
        /home/javier/.rvm/gems/ruby-2.0.0-p0/gems/sass-3.2.8/lib/sass/plugin/compiler.rb:266:in <code>watch': uninitialized constant Listen::MultiListener (NameError)<br>
            from /home/javier/.rvm/gems/ruby-2.0.0-p0/gems/sass-3.2.8/lib/sass/plugin.rb:107:in</code>method_missing'<br>
            from /home/javier/.rvm/gems/ruby-2.0.0-p0/gems/sass-3.2.8/lib/sass/exec.rb:452:in <code>watch_or_update'<br>
            from /home/javier/.rvm/gems/ruby-2.0.0-p0/gems/sass-3.2.8/lib/sass/exec.rb:315:in</code>process_result'<br>
            from /home/javier/.rvm/gems/ruby-2.0.0-p0/gems/sass-3.2.8/lib/sass/exec.rb:41:in <code>parse'<br>
            from /home/javier/.rvm/gems/ruby-2.0.0-p0/gems/sass-3.2.8/lib/sass/exec.rb:21:in</code>parse!'<br>
            from /home/javier/.rvm/gems/ruby-2.0.0-p0/gems/sass-3.2.8/bin/sass:9:in <code>&lt;top (required)&gt;'<br>
            from /home/javier/.rvm/gems/ruby-2.0.0-p0/bin/sass:23:in</code>load'<br>
            from /home/javier/.rvm/gems/ruby-2.0.0-p0/bin/sass:23:in `'  </p>
      </blockquote>
    </blockquote>
  </blockquote>