I've heard of a few systems that help you manage this kind of thing. Most people use git, but there's also cvs, svn, hg, perforce, bzr, and probably some other

I've heard of a few systems that help you manage this kind of thing. Most people use git, but there's also cvs, svn, hg, perforce, bzr, and probably some others in use that I'm forgetting. Leave the history to those tools, they make it easy to change things as much as you'd like without losing work. Don't work against them with policies like this.