Excel: Merged cells now report like normal cells (i.e. their content is announced) but their address range is also still announced. Previously merged cells were reported as selected cells.
* getCellAddress now reports address ranges in a human readable way (i.e. a1 through b1, rather than a1:b1).
* There is a new ExcelMergedCell NVDAObject which is based on ExcellCell but replaces cellCoordsText to get the address from the cell's mergeArea instead.
* ExcelMergedCell is used if Excel's current selection's mergeCells property is true.