Fix import of negative relative row reference from xls.
Fix import of negative relative row reference from xls.

Change-Id: Ibaa325396a8a06c45cf59af9809ed5cbff6d10d0

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