Clarify licensing

[ssbarnea]

Fixes: #1188

[gundalow]

@ssbarnea Thank you for updating this.

I'm just putting -1 till I get someone else to review this.

[gundalow]

@tadeboro Thank you for raising this (via #1188) how does this working sound?

[ssbarnea]

@gundalow While this explanation does not have any legal value, it would worth contacting our legal team for feedback on licensing.

I am also quite curious to find about other Python packages that faced the same issue. I really doubt that dynamic languages that do not effectively embed any code from the GPL dependency are affected. In the end the string of bits, as source or package does not contain any GPL code and producing it (archiving) does not make use of any GPL code, so no lawyer would ever be able to win.

On the other hand, the reality is that you cannot make practical use of the project without also installing the GPL bits.

AFAIK, that counts as weak-dependency but it worth being documented in order to avoid confusions.

[acozine]

I've tried to make the license statement easier to read and understand. Have I retained the correct meaning?

Once we've agreed on the wording, it would be nice to add links to the licenses in the text.

[tadeboro]

The additions do solve the main issue I had: knowing what license applies to contributions. But because IANAL, I have no idea if this is enough to satisfy the GPLv3 requirements.

[abadger]

This is the clearest wording I've ever seen concerning this issue. Well done ssbarnea and acozine!

This looks like it agrees with the legal advice the lawyers have always given me about similar licensing situations. +1 from me on that count.

[gundalow]

Given @abadger's comment I'm changing my -1 to +1
Thank you all

[gundalow]

Tracking like this is a great idea, thank you