bugfix, the functions
  mbus_data_record_storage_number()
  mbus_data_record_tariff()
  mbus_data_record_device()
did return bogus random values, because of uninitialized variables
Merge pull request #69 from schnurksel/fix_storage_unit_tariff_calculation

bugfix storage/device/tariff caculation
Merge remote-tracking branch 'upstream/master'