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.


Yes, we could. Should we (now)?

I agree since we're replacing the resource loader by AMD, it seems really cool changing everything to be AMD-styled. Although, it adds no value to the test itself, since we don't use `css!` in our sources.

Ideas?