RFC: refactor save(),checkout() and link() methods
RFC: refactor save(),checkout() and link() methods

This way it is much more clear.

Signed-off-by: Ruslan Kuprieiev <f6538312ce47017d734b1357aabc970ebf896e32@gmail.com>

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