PureRenderMixin BSD+Patent license issues #560

Hi,

We are using the package rc-util through various nested dependencies, and it becomes difficult for us (and also for other users who have problems with the PATENTS agreement) because of the BSD+Patent license from the library PureRenderMixin:
https://github.com/react-component/util/blob/master/src/PureRenderMixin.js

It would be great if you can upgrade the library to re-release one with MIT license:
https://github.com/facebook/react/blob/v15.7.0/old_major_packages/15/react/lib/ReactComponentWithPureRenderMixin.js

Old news links from 2017 regarding the relicensing:
https://engineering.fb.com/2017/09/22/web/relicensing-react-jest-flow-and-immutable-js/
https://legacy.reactjs.org/blog/2017/09/25/react-v15.6.2.html

Best,
Haifeng