Handling of "O" line code

[WolfgangFahl]

In my QIF exports for investments the O line_code holds examples such as:

O0.00|0.00|0.00|0.00|0.00|0.00|0.00|0.00|0.00|0.00|0.00|0.00

while the standard meaning seems to be "comission" and a decimal is expected.

Currently I can live with my error list being cluttered with these problems. It would be nice to have a cleaner solution.