Surfaces unit tests
The Tests/Surfaces are updated to test all methods of:
- BoundaryCheck
- LineSurface
- RectangleBounds
- Surface
- SurfaceBounds
In some cases baseclass-derived stubs have been created to test only methods implemented in the base class. Some tests are marked as 'expected to fail', but the issues require further attention. Further reorganisation should be required to factor out commonalities; this should be done after more tests are written.