Refactoring

> Originally at https://github.com/kevin-brown/mousetrap/pull/1

This is the pull request that will be used for code review, tracking progress, and eventually generating the patch set for this refactoring.
First, these dimensions are just suggestions. I think they are maximums. The actual size can be determined by the image read from the camera.

I did have some detection trouble, but I found that reducing the scale factor to 1.3 or even 1.1 helped. At this point, it works fairly well on my system, as long as I'm looking square, straight up-and-down, at the camera with good lighting.

If larger images help, we could capture and process larger images, and scale down images when we go to display them.