Replaced projCS 30591-92 with projCS 30791-92.  Deleted geogCS 4305 4812 geod datum 6305 6812. Added geogCS 4819 and to v5 only geod datum 6819.  Renamed tfm 1255 (and in v4.5 geod tfm 8158) from Voirol Unifie... to Nord Sahara....