A "little" component is the most basic component: it supports options merging.
A "model" component is a little component that additionally provides supports for any model defined in the components options.
An "evented" component is a little component that additionally instantiates event firers based on events declared in the options.
A "view" component is an evented model component that supports a view.
A "renderer" component is a vew component that bears a renderer. (see: Renderer Components, for info on extra events and functions added by the rendererComponent typeThere are additional features provided by this component type specified on the Useful functions and events section of the Renderer Component page
Need to specify what defaults each grade defines