add View layer
expose data members of all classes in clump module as public

Data members are intended to be read-only. Although this exposes
implementation details, the clump layer needs to be kept simple.
Sophisticated interpretation of the data belongs to the next layer.
terminology: "view" --> "shape"

Before, views would be wrapper objects around clumps, and higher
layers would need to manipulate clumps and shapes separately.

This thinking has changed: higher layers will only manipulate shapes,
leaving the clump layer to be touched only by the shape layer.