title: Shouldn't JSON.stringify escape Unicode characters?
body: <p>I have a simple test page in UTF-8 where text with letters in multiple different languages gets stringified to JSON:</p>
  
  <p><a href="http://jsfiddle.net/Mhgy5/">http://jsfiddle.net/Mhgy5/</a></p>
  
  <p>HTML:</p>
  
  <pre><code>&lt;textarea id="txt"&gt;
  検索 • Busca • Sök • 搜尋 • Tìm kiếm • Пошук • Cerca • Søk • Haku • Hledání • Keresés • 찾기 • Cari • Ara • جستجو • Căutare • بحث • Hľadať • Søg • Serĉu • Претрага • Paieška • Poišči • Cari • חיפוש • Търсене • Іздеу • Bilatu • Suk • Bilnga • Traži • खोजें
  &lt;/textarea&gt;
  &lt;button id="encode"&gt;Encode&lt;/button&gt;
  &lt;pre id="out"&gt;
  &lt;/pre&gt;
  </code></pre>
  
  <p>JavaScript:</p>
  
  <pre><code>​$("#encode").click(function () {
      $("#out").text(JSON.stringify({ txt: $("#txt").val() }));
  }).click();
  ​
  </code></pre>
  
  <p>While I expect the non-ASCII characters to be escaped as \uXXXX as per the <a href="http://www.json.org/">JSON spec</a>, they seem to be untouched. Here's the output I get from the above test: </p>
  
  <pre>
  {"txt":"検索 • Busca • Sök • 搜尋 • Tìm kiếm • Пошук • Cerca • Søk • Haku • Hledání • Keresés • 찾기 • Cari • Ara • جستجو • Căutare • بحث • Hľadať • Søg • Serĉu • Претрага • Paieška • Poišči • Cari • חיפוש • Търсене • Іздеу • Bilatu • Suk • Bilnga • Traži • खोजें\n"}
  </pre>
  
  <p>I'm using Chrome, so it should be the native <code>JSON.stringify</code> implementation. The page's encoding is UTF-8. Shouldn't the non-ASCII characters be escaped?</p>
  
  <p>What brought me to this test in the first place is, I noticed that <code>jQuery.ajax</code> doesn't seem to escape non-ASCII characters when they appear in a data object property. The characters seem to be transmitted as UTF-8.</p>