Allow removing and re-adding Components.

Changed ```remove()``` to remove a Component from the DOM, but not destroy it nor to disconnect it from the IBroadcasters it was listening to.

ComponentGroup now has ```removeComponent()``` to remove a specific component from the ComponentGroup and the DOM.

```destroy()``` replaces the previous functionality of ```remove()```, which disconnects a Component from the DOM, disconnects it from all the things it was listening to, then nulls out its element.

Attempting to ```anchor()``` a Component that's already ```anchor()```-ed no longer throws an Error. Instead, the Component will be re-```anchor()```-ed to the new DOM element.