make SUMIFS work
flatten SUMSQ
flatten arrays of SUMX2MY2
flatten the rest of SUM formulas
flatten arguments of AVEDEV
flatten arguments of AVERAGE
flatten arguments of AVERAGE and AVERAGEA, ignore non numbers in AVERAGE, add utility NUMBERS function that returns the numbers in an array
test true and false in AVERAGEA
flatten AVERAGEIF
less eval in AVERAGEIFS
cannot make AVERAGEIFS work with multi dimensional arrays, comment that
COUNT must only count non empty cells, and admit multi-dimensional arrays
do not admit ''
flatten arguments of COUNTBLANK, optimize access to range element
COUNT must only count numbers (http://office.microsoft.com/en-001/excel-help/count-HP005209026.aspx)
flatten arguments of COUNTA
flatten arguments of COUNTIF
fix COUNTIF and flatten its range
use array in COUNTIFS
flatten arguments of COUNTUNIQUE