bnc#755775: Set numeric formula results when importing xls document.
bnc#755775: Set numeric formula results when importing xls document.

Without this, calculation upon import may incorrectly show #VALUE!
in some cells when the iterative calculation option is turned on.

This is on par with what we do during the ods document import.

JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core