This is similar to the error code ODF filters are using in sw/sc/sd,
except that it is not specific to any application, so any UNO filter can
use it. All you need to do is to throw io::WrongFormatException with a
"<row>,<col>" in the message of the exception, and then the error dialog
will show it, instead of the useless general error message.

Change-Id: I279c8d438f01498b44f14a6dc6aeef85f7dfa4e4