This involved fixing a bug where the vtkContextScene's Geometry
could end up set to (0,0) despite the fact that the ContextItem
already had a properly set Geometry.

This commit also removes a debugging executable from the Testing
CMakeLists.txt file, and removes some debugging print statements
from the test.

Change-Id: I866b00c24d3df144fa0303de54b4a0d66989bb82