Log Message:
ristretto: update to 0.8.3.

- take maintainership

- Fix GLib-GObject-CRITICAL in directory monitoring code
- Fix loading image from an URL
- Freeing memory used for storing bg colors was done wrong (bug #13335)
- Fix opening image files that are symlinks (bug #13576)
- Fix BMP files failing to load with libmagic (bug #13489)
- Port to GDBus
- Translation updates..