title: Error decoding mixed encoding JSON string
body: <p>I have trouble parsing a <code>dict</code> with a <code>list</code> that contains both <code>ascii</code> and <code>unicode</code>. This is my pretty string: </p>
  
  <pre><code>pretty_string = """{
      "list": [
          "this_keyword_in_ascii",
          u"\u0627\u0644\u0623\u0633\u062f",                  # unicoded arabic
          u"\u0633\u0648\u0631\u064a\u0627",
          u"\u0627\u0644\u0625\u0631\u0647\u0627\u0628"
      ]
  }
  """
  </code></pre>
  
  <p>I get the following error when decoding with <code>dict = cjson.decode(pretty_string)</code>: <code>DecodeError('cannot parse JSON description')</code>.</p>
  
  <p>I've tried <code>pretty_string.decode('unicode_escape')</code> to no avail.  Please help!</p>