xmloff: cleanup StyleMap
xmloff: cleanup StyleMap

Change-Id: I487ab62f412512b0437e6b46a01a3be7c88f5760

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