Undo System

[horvathaa]

Features and how they should interact with "undo":

• Wrapping a new variant
  • "undo" should dissolve the variant - DONE
• Switching between versions
  • "undo" should switch the view to the previous version
• Toggle comment button
  • "undo" should act the same as hitting the button again (if "undo" after commenting out the section, uncomment and vice versa - DONE
• Renaming variant
  • Should revert to the previous name - DONE
• Editing code within a variant
  • Should work as one would expect, when code is changed it can be undone
• Dissolving a variant (not a feature currently implemented but probably should exist)
  • Should reform variant as it was, versions and all
• Paste a variant (not a feature currently but should exist)
  • Should remove the copy/pasted variant