Add timeslider

[tranek]

Allows a client to go back in time and review previous edits. Moving the timeslider does not change the state of the actual sketch.

Add an option to allow editing previous states to fork the sketch (vs not saving any edits on previous states - default to fork).

Marking this as a requirement as a future version should definitely have it.

[brylie]

This is a cool idea @tranek. What changes would need to be made to the data structure? How do you envision users editing the drawings?

[tranek]

Hi @brylie, I'm no longer working on this project. This was almost two years ago and I don't really remember much about it. Sorry!