Undo-Redo sequence of land editing crashes
Editing land heights in OpenMW-CS, then doing undo<->redo causes a crash. It seems like the crash occurs when dealing with destructor of
std::unique_ptr<CSMWorld::RecordBase, std::default_delete<CSMWorld::RecordBase>>, after the destructor of TouchLandCommand is called twice in a row. It may be related to command macros of terrainshapemode.cpp.