Drop jQuery support

In my opinion, this is too opinionated for something like TraceKit. TraceKit is a great library that provides functionality for other ligher levels libs to utilize.

With my recent commit of TraceKit.wrap(), that kind of paves the way for others to use it in a way to wrap anything they want. In the case for us (raven-js), I'm going to be providing a bunch of plugins to patch common libs that a user can pick and choose from. I'd rather not include source for jQuery for someone who isn't using jQuery.

I hope this makes sense. If anything, document the code that was removed and include it as a separate file so it still exists, but isn't so tightly coupled.