Nudge scans in to correct position.

[malcolm_smith]

More often than not, I can use manual registration to get scans registered roughly in the correct position, but they will be up to a few hundred mm out of alignment. I would like to be able to nudge them into position along the x, y and z axes. What I envisage is to choose a scan, specify an increment to move it by, rotate to the view plane you wish to move it in and use the keyboard arrow keys to tap it into position.

This idea was initially posted on the discussion page, where it received some support.