SONUpgradeToVersion6

  Obsolete function
  Upgrades SON file ADC and ADCMark data to SON version 6. 
  File header date and time fields are not upgraded
  The file header creator field is set to 'MAT-TO-6' but only if it is '00000000' to begin with.
  IT IS RECOMMENDED THAT YOU BACKUP FILES BEFORE USING THIS ROUTINE.