To install this package, run in Emacs:
M-x package-install RET vc-backup RET
Find here a VC backend that uses backup files for versioning. It is recommended to enable `version-control' and related variables, to make the most use of it. To install this VC backend, evaluate (add-to-list 'vc-handled-backends 'Backup t) or add it to your initialisation file. There is no need or ability to manually "commit" anything, as backups should be generated automatically. To force a backup, read up on the documentation of `save-buffer'. Backups can be viewed using the command `vc-print-log'.