auto binning, smoother membranes, better -save-progress

This is a big update.
Many features were added, and changes were made:

• Binning (resolution reduction) is now automatically enabled whenever the features you are trying to detect are larger than ~4.3 voxels wide. (This change was made to address the problem of high-resolution images. As more and more Cryo-EM tomograms are generated with sub-1nm voxel widths, this is a huge problem because the tensor-voting algorithm scales horribly with image resolution.) This should practically have no effect on the accuracy of the detector. Nevertheless, the auto-binning can be disabled using the "-bin 1" argument. (And a warning message is printed to the terminal informing users how to disable auto-binning.) Auto-binning is also enabled when using a blob-detection algorithm to search for blobs that are much larger than 1 voxel wide.
• The "-surface" argument has been renamed to "-membrane". ("-edge" detection also generates surfaces, so I wanted to generalize the notion of what a surface is to include both ridges and edges.)
• When creating PLY files containing surface mesh geometry, the coordinates are now projected onto the actual surface (with sub-voxel accuracy). Voxels which are more than 1 voxel away from this surface (actually sqrt(3)/2 voxels away) are ignored by default. (This can be overridden using the "-max-distance-to-feature" argument.) This will have a big effect on the quality of the surfaces generated.
• When using "-load-progress", you no longer have to re-specify all of the arguments.