Not hard, but a bit time consuming. If you know a little bit of Python you can dive in the source code yourself and try to implement this functionality. All you have to do is create a timer and call the save function already implemented every time the timer expires. Just one catch though... you must call the save function with a different argument so that it won't save the project over the same file. Auto-save should always save in a temporary file so that if the software crashes, next time you open your project, you can recover from the temp save file that was created. Also, when the user quits, or manually saves the project, the temp file must be deleted.
Well, I think I pretty much explained everything that needs to be done. Now it is just a matter of translating that into code =)
That`s fine. I`m learning Python. Next i try to implement this function. Thanks!