Check combineLatest types on reactiveNextOperator

[appsforartists]

reactiveNextOperator injects {upstream: Observable<T>} into combineLatest, which is currently typed to be D (the inputs dictionary). The inputs kwarg shouldn't require upstream. When I tried to use reactiveNextOperator, TypeScript was complaining that I hadn't passed in upstream in inputs.

I just took a quick stab at fixing this in http://codereview.cc/D3451, but I didn't dig in deeply enough to verify they're correct.