AJAX2

Ajax2 uses XMLHttpRequest2 which supports FIFO events. Instead of
returning the XHR object directly, it returns a zepto wrapped object
with custom methods to add context-aware callbacks.

Allows use of post-execution callbacks similar to those of the jQuery AJAX object:
http://api.jquery.com/jQuery.ajax/#entry-examples

Documentation will come if merged into the main Zepto.JS

NOTE: jsonp has been deprecated and removed. AJAX2 is now focused around CORS for cross domain calls.