Remove requirement from adding items to constructor

[crutchcorn]

Right now, there's a requirement to have two items in your constructor if you intend to use props in the @Setup directive:

@Setup((props, detectChanges) => {
  // ...
})
@Component({
  selector: 'test'
})
class TestComponent implements OnChanges {
    // These two items in your constructor are required, currently
    constructor(private componentFactoryResolver: ComponentFactoryResolver, private cd: ChangeDetectorRef) {
    }

    // This is required, even if empty
    ngOnChanges() {}
}

These two items are confusing to new users, a bit janky of a requirement, can cause bugs when not present, and is generally just subideal for the usage of the library. I would love to figure out a way to remove these from the consuming component constructor