Support for automatic announcement of row and column headers in Microsoft Excel....

Support for automatic announcement of row and column headers in Microsoft Excel. Fixes #1519. Use NVDA+shift+c to set the current row as the row that contains the column headers. NVDA+shift+r sets the current column as the column containing row headers. Pressing either of these scripts twice in quick succession clears that particular setting. Report table column and row headers must be also turned on in Document formatting settings for this to function correctly.