new features to improve calculation speed: "-save-progress" and "-bin"

The "-bin" and "-save-progress" arguments (features) have been added and documented. They are tested and are working. Both of these features should dramatically speed up the process of tensor voting.

This is a big update. These two features should go a long way toward finally making membrane detection (tensor-voting) fast enough to be feasible for moderately large, high-resolution images.

I finally no longer completely hate this software every time I have to use it. (That said, using this software remains very slow tedious and painful, and usually just as much work as manual segmentation. I still have not yet implemented fast, steerable filters.)

Code for several new filters (for detecting curves and edges) has also been added (and documented with warning caveats). But those new features have not been tested and probably do not work.