Commit 8dddf56 inadvertently removed the ability to omit the width
and height arguments to the OFFSET function. And #REF! is returned
because the function is validating that the new $pCell argument
is present. It is present, but it has been passed in the $height position.
We fixed this by always passing $pCell at the last position and filling
missing arguments with NULL values.
Fixes#561Fixes#565
This change adds support for newer functions that are prefixed
by _xlfn. (#356). The calculation engine has been updated to
recognise these as functions, and drop the _xlfn. part.
It also add a couple of the new functions such as STDEV.S/P,
MODE.SNGL, ISFORMULA.
Fixes#356Closes#390
Mark Baker