vio2sf source from https://git.lopez-snowhill.net/chris/vio2sf
Sync to 1d68801f5f (2 May 2019)

Old source:
- https://bitbucket.org/kode54/vio2sf (e0501e3 (12 Dec 2017))
- https://g.losno.co/chris/vio2sf (1d68801f5f (2 May 2019))
