title: grunt watch task block the command line
body: <p>I'm new to grunt, still learning, so I came up to a very strange problem.
  When I run <code>"watch"</code> task, my command line becomes blocked, so basically I cant do anything on it.
  Bare in mind that the task is completed with success.
  This is my command line output:</p>
  
  <pre><code>C:\server\css-test&gt;grunt w
  Running "watch" task
  Waiting...OK
  &gt;&gt; File "compass-examples-master\02\sass\screen.scss" changed.
  
  Running "compass" (compass) task
  unchanged compass-examples-master/02/sass/ie.scss
  unchanged compass-examples-master/02/sass/print.scss
  overwrite compass-examples-master/02/stylesheets/new/sass/screen.css
  
  Running "watch" task
  
  Completed in 1.496s at Fri Mar 22 2013 19:31:37 GMT+0100 (Central Europe Standard Time) - Waiting...
  </code></pre>
  
  <p>As you can see, all I do is run <code>"compass"</code> task, it completes successfully.</p>
  
  <p>Insertion point keeps blinking on after the <code>Waiting...</code> text part, but keyboard input doesn't work.</p>
  
  <p>My grunt configuration</p>
  
  <pre><code>module.exports = function (grunt)
  {
  
      grunt.initConfig({
          pkg: grunt.file.readJSON('package.json'),
          compass: {
              dist: {
                  options: {
                      sassDir: 'compass-examples-master/02',
                      cssDir: 'compass-examples-master/02/stylesheets/new',
                      imagesDir: 'compas-examples-master/02/images',
                      boring: false,
                      outputStyle: 'nested',
                      require: 'sass-media_query_combiner'
                  }
              }
          },
          watch: {
              files: 'compass-examples-master/02/sass/*',
              tasks: ['c']
          }
      });
  
      grunt.loadNpmTasks('grunt-contrib-watch');
      grunt.loadNpmTasks('grunt-contrib-compass');
  
  
      grunt.registerTask('c', 'compass');
      grunt.registerTask('w', 'watch');
  
  };
  </code></pre>