Follow EU VAT Rules (for event in Belgium)

[stephanj]

Describe the bug
The following EU VAT rules apply for Belgium (and probably other EU countries)

• B2B : Belgian customer : VAT 21%

• B2B : Customer in EU (not Belgium) : No VAT + message

• B2B : Outside EU : No VAT + message

• B2C : Always 21% VAT

The registration for a (Belgian / EU) event should follow this, which is currently not the case.

[cbellone]

Should be fixed now.
I have added an additional config option, in the "EU-Specific invoice settings" section

the default for this flag is true, for backward compatibility, so in order to comply with Belgian rules you have to set it to false