merged @raine's fix for non-option arguments
merged @raine's fix for non-option arguments

ChristianMurphy/yargs,yargs/yargs,jvdm/yargs,bcoe/yargs,sgentle/yargs,yargs/yargs,nexdrew/yargs,geophree/yargs,tepez/yargs,dkoleary88/yargs,rstacruz/yargs,ammeep/yargs,bcoe/yargs,ggoodman/yargs,tepez/yargs,LoicMahieu/yargs,yargs/yargs,elas7/yargs,dkoleary88/yargs,nexdrew/yargs,jean-emmanuel/yargs,oti/yargs,elas7/yargs,zkat/yargs,etiktin/yargs,ammeep/yargs,jean-emmanuel/yargs,geophree/yargs