support "processData" option for $.ajax()

The "processData" option determines whether data should automatically be
serialized to string. Defaults to true.

Closes madrobby#595

src/ajax.js

@@ -136,7 +136,9 @@
     // Whether the request is to another domain
     crossDomain: false,
     // Default timeout
-    timeout: 0
+    timeout: 0,
+    // Whether data should be serialized to string
+    processData: true
   }
 
   function mimeToDataType(mime) {
@@ -152,7 +154,8 @@
 
   // serialize payload and append it to the URL for GET requests
   function serializeData(options) {
-    if (isObject(options.data)) options.data = $.param(options.data, options.traditional)
+    if (options.processData && isObject(options.data))
+      options.data = $.param(options.data, options.traditional)
     if (options.data && (!options.type || options.type.toUpperCase() == 'GET'))
       options.url = appendQuery(options.url, options.data)
   }

test/ajax.html

@@ -250,7 +250,6 @@ <h1>Zepto Ajax unit tests</h1>
           }
         })
       }
-
     })
 
     var OriginalXHR = $.ajaxSettings.xhr
@@ -413,6 +412,16 @@ <h1>Zepto Ajax unit tests</h1>
         t.assertEqual('hello=world&array=1&array=2&array=3&object=[object+Object]', MockXHR.last.data)
       },
 
+      testProcessDataDisabled: function(t) {
+        var data = { country: 'Ecuador' }
+        $.ajax({
+          data: data,
+          processData: false,
+          type: "POST"
+        })
+        t.assertIdentical(data, MockXHR.last.data)
+      },
+
       testDataIsAppendedToGETURL: function(t) {
         $.ajax({ url:'test.html', data:'foo=bar' })
         t.assertEqual('test.html?foo=bar', MockXHR.last.url)