TUTORIAL: Disable Auto Save, Versions and bring back Save As
1. Quit the app(s) you want to configure.
2. Launch Terminal.
3. Paste the command below in the Terminal window, then replace 'name of app' with the name of whatever app you want to configure (e.g. 'textedit'), before hitting Enter:
defaults write -app 'name of app' ApplePersistence -bool no
Alternatively, you can configure all apps at once with the following command:
defaults write -g ApplePersistence -bool no
I don't recommend doing this, though, because, for some reason, it slows down the login process considerably.
For TextEdit only, you also need to run another command, as a workaround for errors that prevents it from functioning correctly:
defaults write -app textedit AutosavingDelay -int 0
4. Relaunch the app(s).
5. Enjoy you considerably less infuriating Mac! 😉
If you don't see any changes, a relogin will in most cases do the trick (if not, the app probably uses a non-standard saving mechanism).
Please note: Although this brings back Save As in most apps, this is sadly not the case with Preview and iWork.
To undo any of the above commands, run:
defaults delete -app 'name of app' ApplePersistence
defaults delete -g ApplePersistence
defaults delete -app textedit AutosavingDelay
P.S. If you want to remove data already stored by Versions, you need to delete the hidden .DocumentRevisions-V100 folder in the root directory of your disk(s).
Apple is dead to me.