Did not touch imstkPbdModel as it's being worked on by andrew wilson

add test for scalar functions on geometry that is being changed
add wip fix

ENH: Textures can be init'd from ImageData, they can be modified at runtime, you can also swap textures

REFAC: SceneObjects and VisualModels can now be both added AND removed to the Renderer during runtime, new event based scene modification/observer pattern

REFAC: KeyPressEvent renamed to KeyEvent, TetrahedralMeshRenderDelegate topology change fix, plane to surface mesh function added to geometry utility

ENH: ModuleDrivers, Modules added. Geometry transforms. Multi viewer support. LevelSetModel, LevelSetCH, EventObject, DataArray, Controller, VisualObjectImporter improvements/changes

Fix PBR textures and add colors