UUID/ID vs Invoice Number

[stephanj]

Is your feature request related to a problem? Please describe.
FYI - For Devoxx Belgium I had to remove all the public references to UUID's en (internally used) ID's and replaced them with the invoice number instead. We use invoice numbers as the public & internal references for all communication and admin follow up.

Describe the solution you'd like
Would be great if this could either be a configuration option, for example: Use invoice numbers for public references. Or just remove any public ID's with the invoice number by default.

Describe alternatives you've considered
Alternative is having a fork (which is what I do now) of the ALF.io project.

[cbellone]

can be implemented as part of #472

[cbellone]

should be implemented. This behavior can be activated by setting the "use invoice number..." option