Comments clean up.
First draft including formulas per row management

Problem with side effect to 'static' formulas being affected by row
shifting while we do want to keep static references for these formulas.
Solved static formula affected by row shifting on dataSheet by using a
temporary "fakeSheet" to compute shifted formulas without side effect on
dataSheet.
Final draft including formulas per row management

Fixed problem with side effect to 'static' formulas being affected by 
row shifting while we do want to keep static references for these 
formulas by making use of a temporary sheet.