unprotect: copy should preceed the move
unprotect: copy should preceed the move

It is better to make a file copy before moving it, since move is
a nearly-atomic operation and copy is a long one.

Also the biggest problem here is that if some application would access
the file during the process of `copyfile` then it would get the part of
file.

dmpetrov/dataversioncontrol,dataversioncontrol/dvc,efiop/dvc,efiop/dvc,dataversioncontrol/dvc,dmpetrov/dataversioncontrol