Lack of undo functionality

[peterbjornx]

Currently rompar lacks an undo feature, and there are many actions that are rather annoying to manually undo from the UI, so a reload from a backup or text-file edit is required.

A quick and dirty solution I am implementing right now repurposes the "load from file" code and maintains a stack of previous states for undo that are generated using dump_grid_configuration.

I was wondering if such a solution would be welcomed by the project, or if there are reasons to not use this implementation for undo?

[JohnDMcMaster]

Thanks for reaching out! If:
-Its not too invasive in the code / its reasonably abstracted out
-It doesn't cause performance issues
I'll merge it in