Update the licence to a copyleft licence

[FvD]

We still have the old 2018 copyright!

Indeed, particularly as the license says

"Proprietary
Copyright 2018 ixpantia S.R.L.
All rights reserved. Do not distribute."

So we even must not distribute this via CRAN.

Best,
Uwe Ligges

[FvD]

This was an oversight when we first submitted. The reason we choose AGPLv3 is that we want strong copy-left in place. This is a helper package, it is unlikely to be part of anything that you are buildling or deploying. So for the huge mayority of cases it does not matter that it is AGPL (you would not be including the ixplorer package in your final product, just use it as you are building).

If however the ixplorer package would be part of something that you are buidling, we would like to be able to see what it is. If you have any questions or suggestions about the licencing, please feel free to contac us.