cubicweb #893940 finish undo support [validation pending]

  • undo of entity update
  • better handling of entity add undo (conflict detection) ?
  • replace config by a simple undo-support= yes or no ? would probably be better since we can't properly tell what action should be undoable or not (should be all or nothing in a transaction)
prioritynormal
typeenhancement
appeared in<not specified>
done in3.15.0
load1.000
load left0.000
closed by#486386d9f836 [web] Exposes the undo feature to user through a undo-history view (closes #893940), #9747ab9230ad [repo, undo] Finish repository-side implementation of the undo feature (closes #893940)