improve option occurences counting
improve option occurences counting

stop using ad hoc increment function trick to count occurences of
options - use a 'singleton' increment function for that - easier to
check for a special case

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