Update post effects example to work with updated post effect scripts.
Lights and cameras no longer subclass GraphNode.
Rename light and camera source files. Hide low level camera data structures from the docs since they're no longer considered API.
Remove pc.ForwardRenderer from the docs. It's internal and should not be considered API.
Merge pull request #133 from playcanvas/feature/nodeless-cameras-lights

Feature/nodeless cameras lights