Add an "Undo" feature

[Josh Glassmaker]

Ability to undo last action performed on signatures whether adding, deleting or editing. Possibly even the ability to go back multiple steps.

Maybe even expand via admin feature so an admin can undo anyone's changes.

[Robert Hucks]

This a thousand times. I've accidentally cleared the scan results list more times than I care to admit. I would love this to be a thing.

[Josh Glassmaker]

Added 7/19