Make JasmineTest to allow custom matchers

Modifications to make custom matchers with _JasmineTest_ possible.

I was writing tests for an application which manipulates SVG elements, and I thought it'd be much better if I could write matcher expressions like _toIntersectWith_, _toBeContainedWithin_, _toHaveColor_, and etc.

So, this is what I wrote to deal with the problem, and I'd like to know if it would also help others with similar requirements.

Thanks!