Undo & Redo actions

[hobnob]

Is your feature request related to a problem? Please describe.
As it stands, if an action is done by mistake (player is killed off, for example) then you can't undo that action. In the case of a player being killed off you would have to either reset everything or use a summons (neither of which are great)

Describe the new feature you'd like
Add an Undo action at least (with a redo as well maybe) so that mistakes can be rectified