l10n_nl: order in tax report is undefined

Hi,

in the Dutch chart of accounts, some of the tax codes have an null value for the field 'code'. That means that the order in which these tax codes appear on the tax report is undefined. On some instances it is correct, but on other instances which we run it is perfectly in reverse.

Here are the names of the affected tax codes. As you can see, the code is usually included in the name instead.

 Gegevens omzetbelasting (BTW)
 Gegevens omzetbedragen
 1 Leveringen en/of diensten binnenland (BTW)
 2 Verleggingsregelingen: BTW naar u verlegd (BTW)
 4 Leveringen vanuit het buitenland (BTW)
 5 Voorbelasting, kleineondernemersregeling, schatting en eindtot
 1 Leveringen en/of diensten binnenland (omzet)
 2 Verleggingsregelingen: BTW naar u verlegd (omzet)
 3 Leveringen naar het buitenland (omzet)
 4 Leveringen vanuit het buitenland (omzet)

Cheers,
Stefan.