Blender Git Loki

Made an attempt to improve memory consumption during stroke
rendering. When objects exists out of the viewing frustrum and
near the near clipping plane, feature edges in the 3D camera
coordinate system are projected to an extremely far location from
the camera view in the 2D image space. These feature edges
result in very long strokes with a large number of stroke
vertices, which temporarily require a significant memory storage,
causing a fatal "out of memory" error. This problem is partially
addressed by the changes in the present commit.