Warn against using jQuery.ajaxSetup()

[dmethvin]

We should be strongly recommending against using $.ajaxOptions() since it makes global behavior changes to all ajax requests and therefore can cause unexpected behavior in plugins or other modules that expect the documented defaults. With many options to $.ajax, users also have unmet expectations about whether $.ajaxOptions() should be overridden or instead magically merged/resolved with whatever was passed to $.ajax.

[kswedberg]

$.ajaxOptions?

[dmethvin]

Yes... when i get the wrong name in my head it won't come out.