Fixed incorrect import of cell attributes from Excel documents.
Fixed incorrect import of cell attributes from Excel documents.

When a cell with non-default formatting attribute starts with non-first
row in a column, the filter would incorrectly apply the same format to
all the cells above it if they didn't have any formats.  This commit
fixes it.

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