Tests: Replace resource loader with AMD

:boom: WIP...

Pulll request's goal is to AMDify tests for 1.12.0 release and address part of http://bugs.jqueryui.com/ticket/10119.


Hmmm. Seems like we should have a more elegant way to handle this. Right now, the spec files are listed as `defines`, and the main `require` pulls then all in and executes sequentially. Is there any reason they need to be called sequentially? Doesn't `Qunit.start()` still need to come last? And therefore it shouldn't matter if they are executed serially?

What I mean is, can't you just not export a function and instead just run the code as soon as it's required in?