title: Multiple arguments transition mixin
body: <p>I just want to implement a basic mixin for the transitions, this is my code:</p>
  
  <pre><code>transition()
      transition         arguments
      -webkit-transition arguments
  </code></pre>
  
  <p>Until i use this mixin with a single property all is working fine, but when i try to do something like this:</p>
  
  <pre><code>a
     transition(color 1s, text-shadow 1s)
  </code></pre>
  
  <p>My output is:</p>
  
  <pre><code>a {
      transition: color 1s text-shadow 1s;
      -webkit-transition: color 1s text-shadow 1s;   
  }
  </code></pre>
  
  <p>no commas are added... any suggestions?</p>