Fix the PR

Derivative works is a bit of a tricky subject. As far as copyright law is concerned, anything that includes significant portions of the original, but also has modifications, is a derivative work.

I think I'm going to change my mind on this. Derivative works, in the context of copyright law, should be required to use the same license...because by definition they include portions of the originals.

Note that addons don't fall under the derivative work clause as long as they don't include actual code from the original mod. Eg, I can make an addon that uses an API from the original mod without needing to license my addon under the MMPLv2, but if I include sections of code from the mod, I would need to license my addon under the MMPLv2.

Does that clear some of that up?