jQuery.ajax: Adjust note about cross-domain ajax request with 'JSON' datatype

Fixes jquery#959
Closes jquery#1021

Author: onebytegone

entries/jQuery.ajax.xml

@@ -98,7 +98,7 @@ $.ajax({
             <li><code>"xml"</code>: Returns a XML document that can be processed via jQuery.</li>
             <li><code>"html"</code>: Returns HTML as plain text; included script tags are evaluated when inserted in the DOM.</li>
             <li><code>"script"</code>: Evaluates the response as JavaScript and returns it as plain text. Disables caching by appending a query string parameter, <code>_=[TIMESTAMP]</code>, to the URL unless the <code>cache</code> option is set to <code>true</code>. <strong>Note:</strong> This will turn POSTs into GETs for remote-domain requests.</li>
-            <li><code>"json"</code>: Evaluates the response as JSON and returns a JavaScript object. Cross-domain <code>"json"</code> requests are converted to <code>"jsonp"</code> unless the request includes <code>jsonp: false</code> in its request options. The JSON data is parsed in a strict manner; any malformed JSON is rejected and a parse error is thrown. As of jQuery 1.9, an empty response is also rejected; the server should return a response of <code>null</code> or <code>{}</code> instead. (See <a href="http://json.org/">json.org</a> for more information on proper JSON formatting.)</li>
+            <li><code>"json"</code>: Evaluates the response as JSON and returns a JavaScript object. Cross-domain <code>"json"</code> requests that have a callback placeholder, e.g. <code>?callback=?</code>, are performed using <a href="http://bob.ippoli.to/archives/2005/12/05/remote-json-jsonp/">JSONP</a> unless the request includes <code>jsonp: false</code> in its request options. The JSON data is parsed in a strict manner; any malformed JSON is rejected and a parse error is thrown. As of jQuery 1.9, an empty response is also rejected; the server should return a response of <code>null</code> or <code>{}</code> instead. (See <a href="http://json.org/">json.org</a> for more information on proper JSON formatting.)</li>
             <li><code>"jsonp"</code>: Loads in a JSON block using <a href="http://bob.ippoli.to/archives/2005/12/05/remote-json-jsonp/">JSONP</a>. Adds an extra <code>"?callback=?"</code> to the end of your URL to specify the callback. Disables caching by appending a query string parameter, <code>"_=[TIMESTAMP]"</code>, to the URL unless the <code>cache</code> option is set to <code>true</code>.</li>
             <li><code>"text"</code>: A plain text string.</li>
             <li>multiple, space-separated values: <strong>As of jQuery 1.5</strong>, jQuery can convert a dataType from what it received in the Content-Type header to what you require. For example, if you want a text response to be treated as XML, use <code>"text xml"</code> for the dataType. You can also make a JSONP request, have it received as text, and interpreted by jQuery as XML: <code>"jsonp text xml"</code>. Similarly, a shorthand string such as <code>"jsonp xml"</code> will first attempt to convert from jsonp to xml, and, failing that, convert from jsonp to text, and then from text to xml.</li>