Added support for Sectioned Lists

Please add a TODO here. I think the way we are setting up animations is broken. We should be passing in the animation from the Component so that we can set Animations appropriately in the 

btw - you'll need animation on  the headers as well if you are going to bring them in from below. Just bringing in the cards may not be enough. SO you need some mechanism to define Animation of the Header/Section in the SectionListComponent and inherit the method setItemAnimation from ListComponent.