As far as I know it is no longer available.
The nearest thing to it is what has appeared in 10.0.3 . . . the Backup.
If you look in your Project folder you will see a new folder entitled "Backup".
This saves a copy of your project every 15 minutes but unfortunately it also deletes the previous one.
So there is only one backup, which is great if your project suddenly hands in the dinner pail but not not much use if you want to revert to what you were doing yesterday.
It's a pity someone can't write a bit of code to give you the option of not deleting each Backup.