Excel, error on file opening when large column-width used at tables-/grid-definition

[speckyspooky]

If a report contains a table or grid with a huge column-width and the user create an excel file then an error appears at the moment of file opening. A message will be displayed that there is an issue and excel will start a fxing of it.
But at the end it could be that data will be lost.

Excel message - part 01

Excel message - part 02

Reason:
The problem is caused on the calculation of the column with of excel.
At a specific moment the number type "short" is used and it gives a number overflow (from positiv to negativ, number circle).

I will populate a PR for that.

[speckyspooky]

The fix is merged to the BIRT-master.