Figure out depth image planar workspace version. Where to put?

[pv33]

Currently that code is in the Mary Surveillance codebase. Is that reasonable? It will get used for many other applications. Should consider extracting and placing somewhere more generic.

Might require creating some kind of inDepth and inDepthImage classes. The inDepth may not be needed since the presumption is that it is a scalar depth or range image. We need one that does RGBD streams. maybe inRGBD class. This class would then have detectors for both streams that get fused. Need to figure out how the color + depth registration should work out. Hopefully realsense does it automatically. Would be great to be an internal to camera electronics function, but I doubt it.