It's now possible to enable/disable tone-mapping, fxaa, msaa and
dynamic resolution independently.
A new set/getToneMapping() method is added to View.
It's still possible to disable *all* these post-processing effects
together using setPostProcessing(). This is currently needed when
rendering a transparent view (such as UI) on top of another view.
This limitation might be addressed in the future.
This fixes#621
9daf7aab64