Extend undo levels - or snapshot support

[knolleary]

@moebius

Thanks, i'm aware of the project feature - but it's a little more complicated than pressing "Ctrl-Z"

But equally, why would we implement a parallel system that duplicated what projects can do, but without the same level of functionality?

I think there is a place for a more simplified user experience with projects - something I posted back in January: Feedback wanted: Simplified git workflow