std::move is redundant when it is used to return a local object from a function (eg return std::move(local)): indeed, returning a local object from a function implicitly moves it. Moreover using std::move this way
See https://github.com/isocpp/CppCoreGuidelines/blob/master/CppCoreGuidelines.md#Rf-return-move-local
However, in order to avoid -Wreturn-std-move as well, a Base object is move-constructed
from Derived when required.
Found via `codespell -q 3 -I ../fc-word-whitelist.txt -S ./.git,*.po,*.ts,./ChangeLog.txt,./src/3rdParty,./src/Mod/Assembly/App/opendcm,./src/CXX,./src/zipios++,./src/Base/swig*`
make function undo/redoable
work on document that was active when the dialog was opened
handle case when object or document is deleted while dialog is open
