Improves the use of the ShapeAppearance property for the Part workbench.
removes DiffuseColor property
adds Python compatibility using custom attributes
transitions DiffuseColor to ShapeAppearance on open
Improved UI elements for setting object appearance, and appearance per face
Lays the foundation for future texture support
* Maybe you meant to call Primitive::onChanged() instead [-Wclazy-skipped-base-method]
* Maybe you meant to call Primitive::mustExecute() instead [-Wclazy-skipped-base-method]
* Missing reference in range-for with non trivial type [-Wclazy-range-loop-reference]
* Use multi-arg instead [-Wclazy-qstring-arg]
* Use midRef() instead [-Wclazy-qstring-ref]
