Autosave project

[bathrobehero]

Is your feature request related to a problem? Please describe.
I tend to edit models quite a bit with the slicer and not just slice and go and I usually just leave several projects open and modify them as I print but it sometimes crashes, losing progress. Like with variable layer height on one object but not on another clicking Slice crashes every time.

Describe the solution you'd like
Autosaving the project file. Preferably several rolling autosaves.

Describe how it would work
Each instance of the slicer would create autosaves or backups of the project file every X minutes (maybe only if there were changes) and keep the last Y number of backups. But it would have to differentiate between different unnamed projects, not overwriting each other. Maybe using the file names based on models inside the project or some other unique identifier.

But just any kind of basic project autosaving would suffice.