auto-save files

[herrsimon]

First of all, thanks for this great piece of software! I'm a lecturer and intend to test drive it in some of my classes. It would be nice to add an auto-save feature with configurable time interval. The autosave directory could be $XDG_DATA_HOME/lorien/autosaves, the autosave files themselves could be path_to_a_file if the original file is /path/to/a/file or a simple timestamped generic name in case the canvas has never been saved before.

[flo-schu]

I second that. I'm really enjoying the software so far, but just lost an hour of sketching, because lorien crashed unexpectedly.