Calculated measure functions enhanced STDDEV, VARIANCE, and AVERAGE
'STDDEV2', 'VARIANCE2', 'STDDEVPOS2', 'VARIANCEPOS2', 'AVGPOS', and 'AVGPOS2' variations have been added in function to make standard deviation, variance, and average calculations more useful and flexible. 'POSORNULL' and 'POSORZERO' have been added as new utility functions.