POI：bug 56454: keep XSSFRowShifter#shiftMerged in sync with HSSFSheet: when shifting rows, shift merged regions (even when the merged region does not include column 0)
POI：bug 56454: keep XSSFRowShifter#shiftMerged in sync with HSSFSheet: when shifting rows, shift merged regions (even when the merged region does not include column 0)

antony-liu/npoi,tonyqus/npoi