Wednesday 13th

Decided to take a delve back into the Undo/Redo code today, with little in the way of progress. I did manage to crack a small problem in the logic, however, which was preventing the Undo going right back to the start of the list; essentially, the Editor needs to call the Undo routine at the start of the program, or if a map is loaded into memory - this 'saves' the initial state of the map, allowing the user to Undo back to the beginning.