[0.18.21] Undo in map editor a bit broken

[Illiou]

I'm experiencing two problems with the undo functionality in conjunction with the instant placement functionality in the map editor:

1. If I undo the removal of an entity, that entity is placed as a ghost. Since every other ghost is immediately placed (or rather has the option to) this seems like an oversight.

2. With instant placement enabled, the placement of entities through blueprints, copy or cut is not recorded into the undo history. So if I undo, the action before the placement is undone. In the case of cut this even means the removal of the cut entities is undone but not the placement of them afterwards.

[Rseding91]

Thanks for the report however undo isn't officially supported in the map editor. If it works, that's fine. But I'm not going to be working on fixing any issues found with it. If anything, I would disable it completely while in the map editor if enough people complain about it.