add a marker for save action in undo history

[insaner]

It would be great to have a "document saved" marker of some sort appearing in the undo history so you can just roll back all changes since the last save (not the same thing as "since the document was opened"). This would be useful because you could just click on the right entry in the undo history tree to go back to the last save point, without having to undo each change one by one until you see the title drop the "dirty document" marker.

I think something as simple as a line separator or maybe an entry called "saved" or "document saved" in italics or bold or greyed out (since you can't "undo" a save), or something similar to that would do the trick.