My application has two copyright holders, so I want to be able to specify in the build command whose copyright marks get compiled to the program. D part of the application is built by DUB. DUB configurations would do the trick, but they are already used to define different editions of the application. I have to be able to choose the edition indepently of the copyright holder.

I don't necessarily need two-dimensional configuration. If there a way to order DUB to define an extra D version without altering `dub.sdl` to do that, it would suffice. But is there?

Illustration, I want to choose both an edition and marked copyright holder:

```
configuration "inhouse" {
    targetType "executable"
    versions "InhouseEdition"
}
configuration "salesmen" {
    targetType "executable"
    versions "SalesmenEdition"
}
configuration "internet" {
    targetType "executable"
    versions "InternetEdition"
}
configuration "copyrightcompanya" {
	versions "CopyrightCompanyA"
}
configuration "copyrightcompanyb" {
	versions "CopyrightCompanyB"
}
```