I am using git for my source control. I dont backup media such as gifs, pngs, etc. I am thinking everytime i tag a release it would be a good idea to backup the media files as well. But i dont want to make several copies of the same file each time i create a tag. I'd like an app to handle checking if the file already exists and handles restoring everything to a version i like

What util might i use to do this?

I'm using windows 7.