Move cut tool's slice-line with space (completed!)

While dragging from empty space across a model with the cut tool, I'd like it if the slice-line could be moved while holding space. This would function much like selection in Photoshop, where you can move a selection while you're dragging it (also by holding space), without dropping the selection tool. After you release space you can just keep on dragging out the selection.

Done.

thank you!