Camera transform

NOTE: This is a PR into the camera-master branch where all Camera API changes will go before being merged to master.

`Camera.transform` now works consistently across scene modes. For example, you can assign a matrix created by `Transforms.eastNorthUpToFixedFrame` to it when in Columbus view and not worry about the projection or that the coordinates are different from world coordinates.

The Camera Sandcastle example has been updated to use `Viewer` because the buttons work in all scene modes now.