bnc#862510: PPTX import: Properly show data labels in percent format.
bnc#862510: PPTX import: Properly show data labels in percent format.

Usually, "General" is "0.00" number format, but in this case, when we
want to show percent value, MSO writes that instead of "0%".

Change-Id: I748719765f58e66f9f3fb43c2b527c6823ef6fa1

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